ID1 Form for Voluntary First Registration (original deeds from 1963 and 1968 missing)

Mum has lived in her house since 1983. We collected the deeds from the solicitor but the ones from 1963 and 1968 are missing (only copies or drafts exist). 

If my understanding is correct, identification is not normally required for Voluntary First Registration. However, if deeds are missing then ID is required.

As Mum has deeds from 1977 and her own from 1983, is the completion of ID1 (and verification by a Conveyancer) strictly necessary? 

Thanks

Julia - the identity verification would be with regards missing deeds showing your Mum as the last buyer/owner. If she has that deed but is missing 'older' ones then we would not routinely expect identity verification on submission of the application 
We always reserve the right to request such verification though if we deem it necessary but that decision won't be made until processing starts on the submitted application