I used the leg & gearcase for a 3.5hp one lunger to make a “shift” motor. I think I still have it. Been iver a year since I’ve been in my storage, I’llness you know. Cool lightweight fishing motors. I used blood pressure cuff tubing to seal the shift shaft, They were a little short on gearcase seals, hope your gears arn’t rusty.If you ever install a driveshaft seal, to get to it heat the stainless impeller housing as it’s glued to the gearcase aluminum + removing the shif shaft guide ( aluminum tubr) there is an O-ring under for a shift shaft seal. A 53 7.6hp Firestone was my first motor over 35 years ago. Use red locktite on the three gearcase cover screws & watch for high spots around the threads. They pull out a little after years of tightening. Still have my 1947 Firestone 10hp. Weird driveshaft. twisted stock inside a guide tube.