I came accross EMA Model Supplies Ltd, +44 (0)1932 228228, through my work when I had to produce a scalel industrial pipeline model. They do all sorts of styrene section and sheet, ladders, trusses, tubing, I and H beams, tubing and various 'valves', figures from 1/24 to 1/200, etched brass mesh, gears, sprockets and chain, cams, pulleys, timing belts and matching toothed pulleys, small motors and gear boxes, cements, solvents, moulding kits, extremely small hinges, grain of wheat bulbs and all sorts of tools. I mention them because they seem to do all sorts of things, not necessarily model boat related. No, I have no connection with them at all, other than as a customer.
Mike