Re: 1954 Evinrude Super Fastwin 15

[Don]

There is a company called stevens instruments that makes pressure testers. Yes, they are very expensive. But, I think you can just buy the threaded tips that fit into the gearcase and make your own pressure tester inexpensively.
http://www.stevensinstrument.com/gearcase.htm
PS-Don’t remove that small phillips screw located near the lower oil fill screw! The phillips screws holds the shift linkage in place inside the gearcase. Once that screw is removed you will have to disassemble the gearcase to get the linkage back together. But, now that I think of it, your gearcase may NOT have that small phillips screw. In any event, don’t remove it if is there, until you are ready to disassemble the gearcase.