Well....4 speeds do command a premium over the automatic cars. Add in T-tops and you have a desirable car.
Now, worth the effort? Every car is worth the effort to bring back provided you have enough time and $$$$$$ to devote to the project. From the looks of things you'll need full floor pans - unless you like the Fred Flintstone option, rear quarter skins and some patches up along the rear window channel, patches for the front fenders - behind the wheels, probably door skins, and possibly a cowl. Now that's providing the rear frame rails are still solid.
If you have access to a lift I'd toss it up on one and see exactly what the underside looks like.
Now, even if the frame rails need to be replaced you can get replacement parts from either a parts car or any of the members here who happen to be parting cars. It's just going to take work, welding skills, and time to do it yourself - which will be cheaper than paying someone to do it.
Then you have to consider the rest of the car once you get the rust squared away: Interior, gas & brake lines, fuel tank, rear axle, electrical, etc.
Engine wise, a stock rebuild with machine work costs around $2k in my neck of the woods. I paid over $4k for my 455 build in my Y88 and that was with me supplying a majority of the parts including the block.
So I guess my question to you would be this: Do you think you have the skills (or can learn them) to bring the car back? If your answer is: I'm going to pay someone to do a majority of the work, then I hope you have very deep pockets as its going to take alot of $$$$$ and shop labor to bring it back.