Please remember that this is MY OPINION and is only based on what I think. First the good parts, the TR250 used the TR4A body and the early 6 cylinder engine(TR6). So what you have is not to far from being an actual production car. The transmission and rear end are near the same as the TR4A. I am sure that there had to be a number of small modifications to get the 6 cyl. engine in the TR4( mostly body). But it would not be to extreme, I am guessing.
As to he value. If you had a TR4A in primer, it was rust free, stock and all parts were there, $3-4,000 is a reasonable price if everything works. Likely the big question is does everything work okay in its present configuration. And what possible modifications had to be made to the drive train. If those are minimal then good. If major then be sure that those items are in very good working order or you may find yourself trying to replicate a highly modified part, all on your own.
Lastly as to the long term value. I have noticed over the years that a pure stock car is worth much more than a modified car. Keeping the drive train all Triumph does help a lot here. But do not expect the long term value to reach the same levels as the stock cars. That is unless you find an unusual buyer.
There is some food for thought. Hope it helps.
Charley Fitch
