I don't think you'll be able to re-register it. Depends upon the classification of the write off, but no V5 would make me think it was a B. It should have been broken for parts.......................... You could get a frame with a V5 and transfer the parts over, but it starts to get expensive then. A track bike with no V5 is all it'll probably be, realistically.
Nelly is spot on with this one. Its a cat B, it can never go back on the road. I think the frame number is ground off and the V5 goes back to the DVLA. Make a good track day bike though. Needs to be a lot cheaper unless its very special.
been down this road many a time and some times its more trouble than it is worth, nelly said the right thing by saying you could always reframe it then youll have the log book but all depends on the price of the bike and if you feel it is worth while.