Getting a v5

Hi all, all new to me this. I had to shift my st70 that was in many boxes from a place of work that I'd just got the nod was going bust, that was 8 years ago. Finally restored but fatal error whilst clearing bits out of old place of work, didn't pick up any paperwork or reg plate, it was dark and I probably shouldn't have been there so all done in a hurry before the receivers arrived, cost me a months wages and 3 months of bonuses. So I've got a frame number which doesn't hpi, where do I start? I remember it being on a good old Wiltshire plate - something like JAM416N ,but I've got no proof and I hpi'd that and it came back as a car. Any one got any bright ideas or a V5 for one hanging around, all help most appreciated. Cheers