i just built a hood for my 75, same design as jeo. left the back open for venilation. it is really easier than you think, and cheaper. my roommate and i built a hood for a 75 and a 55 costing about $70 for materials, with wood left over. the most time consuming part is painting/sealing the wood.
i wish i had some pics to show or the measurements but i do not. just make sure its high enough off the water, and plan for some venilation (ie a small fan). good luck and have fun with it!
ps i might be able to find the old measurements, and i will post them for ya.