I turned down a fully resprayed (by Argos cycles) Experto Crede some 11 years ago for £600, it had a right mish mash of components on it but with the half chromed stay and the box lining + paint job by Argos it was a thing of beauty. I couldn't find the serial number in the place it should have been though there was one on the drive side dropout that had been chromed (I thought they were supposed to have one on the forks somewhere as well but I can't remember now.
It was been sold by one person who also had an earlier track frame (Holdsworth £300) that had also being resprayed to its original pomp and put into the LBS window and display area for the EC.
The problem for me was the frame was too small, IIRC it was 21.5", maybe even a 22" which was still a good inch at the very least undersized, I just didn't want to buy it, look at how lovely it was, have to buy a long swan neck stem to get the height length sorted or convert to an ahead, and the thought of simply buying it to flip it the same day flipping it even though it would have been easy money to make a decent wedge just didn't appeal.
I still regret not buying it just so I could look at its beauty but it'd be far better with someone who will ride it and they actually fit to the bike. I've had a few nice frames come my way over the years and most of them have been undersized, so I photograph them for posterity, mull over if it's feasible, get annoyed because it'll look stupid/won't work, sell on and then regret it because it was so aesthetically pleasing!