HELP0... which direction is better?

It's not a super rare car. Yes, the snake skin top and sunroof do make it more desirable, but they don't raise the value all that much. Believe me I know, my '71 GT's are 1 of ~1255, making them far more rare than that gold duster, but they don't typically sell for much more than a similarly equipped Swinger.

The body rot isn't horrible, although you certainly wouldn't get your money back fixing even that. The concern I have is the frame repair that you say it needs. Even though it's not that much more difficult to fix, if you ever want to be able to sell it AT ALL you'll need to replace those rails entirely. Structurally, you can patch a frame rail and have it be just as strong as the original if you do it correctly. I know this and it sounds like you know that as well. But if you say "frame patched" in a for sale ad you can cut your asking price is half, because everyone will assume that it was done poorly and is a sign that the rest of the car is toast.

If you're attached to the car and can do the work, go for it. But you're going to lose time and money compared to buying a cleaner car. Otherwise, I'd be inclined to try and find a roller to purchase on the cheap. Switch over your interior and running gear and hit the road. If you're really inclined, pull the sunroof and swap it over too. The $2,500 to $3k in panels that it will take to fix that car would go a long way to finding a really clean Duster shell, and then you can put your time into something else. I paid less than that for my Duster.