RE: Board - Sail selection
I don't weigh anything like as much as you do, but I've noticed the same thing.
I have a little custom 75 ltr (who really knows the volume as it's a custom) Gorge "no-Nose" board that I sometimes get out on windy days.
I think it may be similar to your Logosz.
It takes quite a bit of "different" technique when compared to the modern wider high wind boards. It takes me a few minutes to "change how I sail" to suit the board, and it's always very frustrating right at first. When I make the right tecnique changes, all of a sudden the little custom gets fun to ride again.
I think you would be surprized at how easy it is to sail a 95-100 liter modern board in the same conditions you used to sail on your OCR.
Something like the Kombat 87 or 97 might really suprise you.
Hope this helps,