Lee,
Nice buy! Why are you worried about the value of a car you just bought? Are you planning on re-selling?
I don't think you are off much with what you paid, as the salvage title reduces the value quite a bit, regardless of the fact that nothing is visible on the body. Also, there are no high dollar modifications (wheels, seats, roll bar, brakes, shift kit, etc. are all not the top of the line upgrades you could go for). I also believe that some of the update bodywork will work against value in today's time where people want the early car look and even convert newer cars to that! Don't get me wrong, this looks like a fun car, especially with the newer engine, but to resell it, you would probaby have a hard time to get mid teens.
I also notice a drip pan under the engine. There is only one reason to do that!
Modified cars are always hard to estimate. Maybe I am off, but that's my two cents. Let's see what others have to say.
Cheers, George