Thanks Tony. The 504 was new to me so now added to the register. The other was on eBay a few months back so I'd picked it up then. When I last looked, it had reached £1600, but reserve not met. That's about what it's worth IMO. Being now at auction, it did give me a photo of the VIN plate though, so I've been able to lift the chassis number. . I like auctions.. I just thought they'd been hidden away for so long you may not have them on the register.
Tony