Sounds like you did really well! Congratulations on a good deal. From my personal experience with these cars, unless it is a low-mile, somewhat rare from the factory-optioned car, you aren't going to kill the value if you want to weld in a Fisher top for the car. With the exception of a Y81 (which I have never had the privilege of owning) I think a Fisher top increases the value on 77-81 cars. I know that they sell faster and bring more money. If the car is not a SE, and you want t-tops, you should do it. Just my .02 on it.