No vin plate no v5

Hi some advice needed, but first the story. Recently a friend of mine asked if I would like to go in on a bike collection with him he had been offered. It turned out to be a complete garage clearance of a deceased estate. The collection was bought in a bit of a hurried affair because as as always two other people were coming later in the day to also make an offer so we needed to shake on it and the deal had to be done there and than. The bikes were in various states of completion and there was a number of V5s. Most used for some kind of competition during the previous owners life. The garage was so rammed that the bike in question was not evident in our rather fast evaluation of what we could see, this is the reason for buying a bike(s) with no documents. The very un secure garage was cleared over six visits each time two vans two trailers. A life's collection indeed. I hasten to add these were mainly BSAs but two Nortons in amongst them, a 88 in road race trim and the bike in question a 750 Commando, also in race trim. In amongst all the spares was a lot of lists and notes that refere to this particular Commando as a Dunstall but how do you tell please?

I have read that a Dunstall could be a full blown rip snorter race race bike to a tank and seat set fitted (which was also found amongst the spares)

My main question and concern is as you have probably already guessed the Commando was one of the bikes with no V5 but neither does it have a vin plate. Does this mean that I can not get an age related plate for it and it will have to remain a race bike. Any advise as to which way to go would be much appreciated.

One more interesting thing, apart from this amazing chance find, is the deceased owner was a avid collector and hoarder of all things relevant to his life and amongst all the boxes of papers was a ammo case with hundreds of old motorcycle race programs going back to the early 60s. The one in particular that I just happened to pick up was one for Darley Moor in August 1991. Blimey! I was a race competitor at Darley then on a 750 Triton I wonder if...... and there he was in the same races as me on his Dunstall Commando!