http://www.drascombe-association.org.uk/DH/Drascombe%20projects/Engine.htm
The solution here is quite simple, so should prove reliable - but the real test will come when its used on the water. It's made from a piece of 6mm dia. stainless steel, which has been bent to 90 degrees at one end and threaded M6. The guide/support is made from a piece of bent 3mm thick HIPs, which is attached by two 6mm machine screws. Note : The lower M/S does need to be cut accurately to length.