Salutary lesson in actually looking at a bike properly before you hand over the cash.
Came with a non standard seatpost / seat which I checked moved freely. The rest of the bike is original so I didn't look too closely at the frame, but when i get home and look at it properly I discover that at some point someone has used heat to remove a stuck seatpost and done (pretty good in fairness) home paint job on the damage.
The problem is that at standard 30.4 seatpost doesn't fit in the tube anymore - its got a 30.00 to 27.2 shim in it so I'll stick a 27.2 in it and cross my fingers.
I suppose I can't complain too much for £30 - I only bought it because I regret selling the one I had earlier in the year