First off, beautiful car!!!! Yes I'm biased (see my avatar). As for what you can get for your car, what other members have mentioned has some validity, but usually there is an intrinsic ceiling to a cars value on the open market. In our hobby, restoration costs don't dictate a realistic selling price. How many times do you hear/read members suggesting to buy a finished car instead of doing a restoration because it's cheaper. Very rarely can you recover your restoration costs when selling a car.
All that being said, the fact that it is a Satellite does lower the value of the car compared to a Roadrunner, even though it is basically the same car. Surprisingly too, since there were fewer 70 Satellite convertibles made than Roadrunner convertibles.
I am on my third 70 Satellite convertible. I sold my first one 25 years ago ( it was my college car), bought my second 15 years ago for $9k (all matching numbers), sold that one 8 years ago for $18k to buy a 70 RR, then bought my current one less than 2 years ago for $22k, also matching numbers. The previous owner did a semi RR tribute when he repainted the car about 10 years ago, removing the Satellite trim and putting in RR tail lights, but no bulge hood. I like that look much better anyhow so I was very happy. There were a few trim pieces missing on it that I have been able to source through the forum.
You mentioned a long restoration on your car. How extensive was it? A total rotisserie job? everything removed rust treated/cut out? Original metal? That does add value to the selling price, but nowhere near what the actual cost was. Do you still have the original 383? Is the transmission the original 727 ( i assume a 727 with the 383, my last 2 were both 318's with 904 trannys)?
Does it have an 8 3/4 rear or the 8 1/4 that the 318's came with? All of these things add value.
My estimate based on my experience is that your car to a non-emotionally attached buyer is mid 20's. I am not that buyer and would pay more for the car based on my personal fondness for 70 Satellite convertibles. If I was in the market for one I would probably pay closer to 30k based on the extent of the restoration and the 440 you put in. But that's me. My opinion is that since you have had the car for 32 years already and did all that work and spent all that money on it, DON'T SELL THE CAR !!!!
You will probably regret it and have a very hard time replacing it. That's just my opinion though and I don't know your personal situation. You have a beautiful and very unique car. Good luck with whatever you decide.