If it is a numbers matching car, I would go for it at the price he is asking. If not, than offer less.
its not going to matter I think, IF he makes it a TA...itisstill numbers , but not 'correct'....
but if you like the car, buy it, make it "your way"...as a friend here in town did, his was a regular convertible, he made it a TA "his way"...used reverse paint scheme etc...
it even says in ghost paint under his rear spoiler....'TA my way'