[RC-Monster Mike]

Any oil bath at all would be a bad idea IMO. Even if it just skims the teeth, it would provide resistance. Also, unless the case is sealed with o-rings, dirt will get into it - oil attracts dirt, so you would effectively have a power robbing gear box that grinds itself to death with this strategy - like a sand blaster. :)
I agree, it is rare to have the set screw fly completely off - which is why I said "occasional" in the initial statement. No explanation needed. It can and has happened - to me even. Not often, but possible. I will also say that I have lost my pinion set screw more often than I have foiled the gears due to the open case/no case. :)

I am reluctant to attempt to quote a date at this point - in addition to a few custom projects for customers, I have my own backlog of "new stuff" that I am trying to work on. I will gladly take look and try to determine a realistic price if you like, though. :)