I built a Dumas Donzi Z65 a few years ago. I ran 800 sized motors on a gear reduction units (turbo trans from FinedesignRC.com) with a 3:1 reduction. That was a nice set up but the gear reductions were pricey. My current scale boat that I have been working on is a Modelslipoways Broom 44. I made my own motor mounts and belt drive reductions from home depot purchased fiberglass bathroom board. I doubled it up with using thick CA and weights. I mapped out my motor and shaft areas. I "milled" everything out by hand with a dremel. That stuff is really strong and its easy to work with a dremel. I do not have pics of wither boat currently, I sold the Donzi, and the Broom 44 is packed up and I havent louched it for a while now. I will be selling it soon for to fund the BIG DOG! I found a local guy that is trying to produce an 1/12th kit of the Nordhavn EYF 75. His molds are about complete and its about to start producing them. If anyone is interested in one, let me know and I can get specs, pics price and lead time. I have seen almost every plug and mold that he has made for this project. I have also seen the model in person. I must say it is a amazing boat. I will have some pics this week

Tom