You couldn't go wrong really as you were picking it up. He said as new condition, so if there were serious problems you could have refused to pay for it. e.g., the eBay picture makes it look as though the seat post is probably stuck - but evidently not, so that's good news.
Tange Prestige Ultimate Superlight was the lightest Tange tubing made, you've got good kit that could still be ok, you might even have the original ti handlebar on there, all for £73.
It looks to be a size 17.5 or 44.5cm, measured c-c, good for 5-10 to 6-0 I would guess.