Personally, I'd say the pro's outweigh the con's at the moment. It's not really costing you much to hang on to it. You can start planning a few different way on how you might do the car up?

You could do a wicked suspension & drivetrain (sounds like it pulls hard as it is) maybe ad a 6-speed and leave the shell as is for that sleeper/daily driver look. You could go all out and real make it trick inside and out, you could go back to stock and have fun hunting down some kool NOS stuff to add to the car...

It's all about the vision, the plan and getting it to that point.
You are in a great position with a killer platform for something very unique and different. You have a solid higher end bird with desirable options and the know how to pull it all together anyway you see fit. Why not start doing a little research and see what direction you might want to take it if you were to do it up right? See if you can get that spark back...

Besides, this is not exactly the best time to be selling... you may get a fair price for her, but by the time you get some more work done on her, the market may be better and the car may be more sought after... give it some time... work on that spark!

Brett - 67 Drop Top 455! (wishing I had many of the cars I've sold)