Ex MOD registration.

Hello all, I’m brand new here and I’m sure this question has been asked before so I apologise in advance.
I need some advice for the sake of my sanity if nothing else.
Some years ago my husband acquired an ex MOD defender 110 and due to complications it was never registered. Now it has fallen to me to complete this task and I’ve hit a bit of a roadblock. Without going into too much detail we had a number of problems getting the vehicle (Who is called Hank btw) fixed up and the work is now being completed by a different garage.
It is currently going in for its mot this week, the snag is that the original mod654 document is lost and potentially damaged/ destroyed. We have a copy of this document along with copies of the bill of sale, invoices for previous work carried out and several previous mot certificates and an original heritage certificate. Has anyone successfully registered a vehicle with copies? If so what did you do and how long did it take?
It’s clear to us now that we are never going to see those original papers again, I have attempted to contact the place my husband originally purchased it from but they no longer have any information on our vehicle and suggested I try asking the MOD directly who sent me to DESA who sent me back to the MOD again and everyone says they can’t help.

If anyone can give me any advice please because we just want our vehicle on the road.
TIA

Have you tried submitting form V55/5 to the DVLA?
I've used this to register an imported vehicle, that had previously never been registered on UK roads.
This may well be documented in a similar fashion.

We are waiting to get it through its MOT before we submit any forms to the DVLA, hopefully it passes first time. I spoke with the DVLA this morning but the person I spoke to wasn’t overly helpful and was told I could send what we have with a covering letter explaining why we no longer have the originals but there was no guarantee. I’m wondering if there anything else we could include/ say that will help.

You could get in touch with the military vehicle trust. They're officially recognised by the DVLA as vehicle inspectors and can get you the registration. Costs about £200 for non members.

Thanks I will look into that, however much it costs is worth it just to get this all sorted out.