I've got a 1989 10 mtr. Love it !!! I don't have the TRS drives, mine came from the factory with SSM IV's on merc boxes. Back in the late 80's and early 90's, I had a few friends that bought these 10 mtr's with 420's and TRS's. Back then, they ran in the mid 70's. They were great rough water boats, I mean they were good to about 4 ftr's, then you were really airborne.
One problem with almost all of the older 10's were the fuel tanks started to leak. Mine did a few years ago, and I found out that Fountain had a problem with the company that was making the tanks for them at that time. In the early 90's, they started making their own tanks at Fountains facility, and there were no more problems with leaking tanks. If you're planning on buying one, ask the owner if the tanks were ever replaced, and if they were, ask for proof. Cause if they wer'nt,

you will be replacing them yourself, almost a guarantee on that.

And it's a big, big job. I'd never do it again.
Good luck on your search for a clean 10 mtr. Once you find one, you'll love it.