Natty little boat. Looks like a cross between a Skipjack and Dutch Walrus class, and going by your description suffered from the same sail induced roll!
Mechanically I don't think things have moved on at all really since you built that- I guess there are only so many ways you can take on and eject water. Electrically we now have much better batteries and luxuries like miniature pitch controllers, which enable us to sail our boats for longer and with greater precision.
A pity you no longer own the original model, I wonder what became of it?
I see from some of the other articles you were a friend of Tom Andrews. I well remember Tom and the miniature boats and subs he used to sail at the Model Engineers Exhibition. I recall a favourite model was a conversion of a small Smitt Rotterdam tug kit, and he often used Cannon R/C equipment quite a bit in his models, which at the time was just about the smallest commercial radio kit available.