You may hate me for saying this, but rare doesn't make it valuable. I've got a fax machine if you need one. Yeah, still no takers and I'm not sure why?
You're talking about a 40 year old boat that you yourself have not used in over 23 years. (maybe never used?)
If it is currently in pieces, then it is even less valuable. Do I think it needs to be restored because of its rarity? Absolutely. You are talking to a die hard Supra fanatic that has too many sitting around and is currently restoring 2 of the best ever made but when all is said and done and the money is spent, they will only be valuable to me...and value being more sentimental than monetary. I have over $12k or more in my Rider restoration but it is not even close to being finished and no way someone comes up with that amount for a boat still in 1000 pieces. Yet, I would be a fool to sell and if I did, it would be for pennies on the dollar. So, in for a penny, in for a pound.
My advice is get to work and restore it so YOU can use it. I don't know your age but trust me, it will all be sold for scrap in the near future cause the generations behind you don't give a damn about it. The generations that grew up with them are a bunch of old men now that have moved on long ago. That 454 is the only piece someone would take in a yard sale. There is just no demand for it and that is what drives the prices of any market.
Unfortunately, the one guy that wants it is on the opposite of the country and shipping/ transportation costs alone would make it too expensive at that price so it is gonna sit in your garage for another long period of time again unless you decide to continue the restoration. Worst case, you can do a Craigslist fire sale on the parts, recoup a few dollars, and then move on.