URGENT - Lease registration issues?

I'm having lots of issues selling my property (Title HD306128) due to the lease.  I had a buyer late last year who's solicitor obtained a copy of the lease from the Land Registry. It was then discovered to have 3 pages missing and after the delays this caused the buyer eventually pulled out.
In the interim I managed to find 2 copies of the lease from when I purchased the property in 2009. The first one looks identical to the one my buyers received with the missing pages and the second copy is complete but has been stamped with "Land registry official copy" dated from 1986.
I found a new buyer about 3 months ago but the lease is once again causing issues. The buyers solicitors have been told that the lease has not been registered with the Land Registry and were told they don't have anything on file, not even the incomplete lease that was supplied late last year. The Free Holder (Management company on behalf of local council) have said they don't have a copy of the lease and my solicitor isn't having much luck getting any help from them.
The buyers solicitors are refusing to progress unless the lease is registered and the new buyer is getting anxious. I can see yet another sale falling through if this is not sorted quickly.
Can it be true that the lease wasn't registered if I have a photo copy of an official land registry copy? Is there anything I can do my end with my photo copy, with my original solicitors cover note stapled to it, to get this sorted?
Many Thanks

Oliver - we don't have a scanned copy of the lease. If you have an official copy from the past that's complete or you/the landlord have an original or counterpart then you/your conveyancer should contact us and attach a certified copy/official copy as appropriate
It reads as if you have been doing the hard yards to find a decent copy but nobody has then contacted us to say that ones been found, can you use that instead
Public guidance: dealing with land and property - GOV.UK

Thanks Adam,
Would my copy be deemed appropriate? It's a photocopy of an official land registry copy from 1986.  Is there anything I need to do to prove it's genuine and if it is acceptable then what would the next steps be?
My conveyancer seems to be dealing with the Freeholder who has already told me they don't have a copy. If there's a way I can just do this myself then that would be great!
Many Thanks

Oliver - that can't be decided until it's submitted and seen. If it's not the actual official copy, an original and/or a copy that can't be certified then I suspect it won't be acceptable
If it's not then you may have to go down the route of having a new lease drawn up to resolve the deficiency unless the buyer's conveyancer accepts the copy you have and an indemnity policy which would be something to discuss with your own conveyancer

In that case do I have any recourse with Land Registry for losing it? I know they had a copy missing 3 pages late last year and I know they had a full certified copy in 2009.  Is there a deeper search of the hard copy archives that can be done?

Oliver - there is a process for submitting what you have and if any recourse is available that will be advised by the support team
I should stress that responsibility for holding/having the lease lies with the landlord and tenant, not HMLR. We don't keep the originals and will have photocopied or retained a certified copy at the time of registration for filing

Thanks Adam. You mention HMLR would have retained a certified copy.  I believe this is what I received a photo copy of in 2009.  The certified copy was made by HMLR in 1986 so would have been in your possession for at least 23 years.
Is there not a way of searching the hard copies/archives for this document?
 

Oliver - that's correct. There is a way of searching. You need to make your request and submission using the contact form as posted previously and then let the process flow

Would that be
"I need to locate deeds relating to a piece of land or property" or
"I need historical information on a piece of land or property"

Also if I want to submit my copy is that 
"Registering property or land for the first time, including leases" or
"Registering or removing an interest in property or land (joint tenancy/tenants in common/restrictions/notices/home rights)"

I assume the lease has already been registered so I'm just trying to update your copy? Or am I registering as if this is the first time?

I've attached the first page of my copy of the lease. Do you think it would be accepted as a certified copy?

I have spoken to HMLR and discovered they lost the documents they originally held and directed me to the "Practice Guide 39 - Rectification and indemnity".  I've been following that but in the meantime I think I may have tracked down an original or counterpart lease that I should hopefully have in my hand tomorrow. If it turns out to be suitable then this will obviously make things much easier.
The person I spoke to at HMLR said "If you are able to obtain a copy of the missing document from another source, I would be grateful if you would lodge it so that we may update our records." but I'm not sure how I go about this or how quickly it can be done.

Do I have to get a certified copy and if so is there a list of people who are allowed to do this? Once I have a certified copy do I send this somewhere through the post or is there an electronic process I can follow?
Thanks

Oliver - I'm HMLR as well and I can see you have asked the support team to respond with an answer to the same Q. They'll do that asap with guidance on how to submit a certified copy and through which channel (post or electronically) as appropriate 
The support team manage and respond to such matters 

Thanks Adam, were you looking at Enquiry 250709-4901857? 
If so I just got a copy and pasted answer that didn't really answer the question. It says

"To certify a deed as a true copy of the original please write on the face of the copy document “I certify this to be a true copy of the original," add a wet ink signature and print the name and address." 

Does this mean I can do it myself or should I be going to a professional like a Notary to get this done?
Many Thanks

Oliver - that explains how you can certify a true copy. Reply to that email with a certified copy attached and the support team, who deal with such specific issues, can then action and respond as appropriate

Hi Adam,
   I've just had the dreaded message that the buyer is pulling out due to the lease delay.  As I managed to track down the original lease I'm going to have one last go at saving the sale but could you let me know if the request to lodge the lease with HMLR has been expedited, and if so how long it is likely to take?

Hi Oliver - your updated enquiry and attachment has been referred to the team who deal with such matters. They will action it asap. It has been escalated

There's no expedite process for such matters as it's not an actual application to create or update the register itself

HD306128

Thanks Adam appreciate the updates.
    The solicitors are talking and trying to buy some more time.
I've just received a response

"in order to reply, we require sight of certain departmental records that are not immediately available. This will result in a short delay."

Does this just mean they need to get some documents sent from somewhere else? Are we talking days instead of weeks as far as "short delay" goes?
 

Oliver - by departmental records they will mean paper files held in storage. They will be retried and scanned into the system for checking - that usually takes 2 or 3 working days depending on numbers/available resource