[SML] Do you have a successful invention?

[christopher R. pike]

I respect the fact that people who use this list have a wide range of
experiences, which is why I'm writing here.

I'm potentially going to file for a patent and fabricate a prototype
of an invention (actually, the plan is, fabricate first, file patent
second).  I would present this prototype to companies with the
capability to manufacture and market, and hopefully license this
product to such a company.  I have a quote from an engineering company
for the fabrication of the first prototype, and it isn't cheap.
(Filing for the patent if much less cost that fabrication.)  Before I
pull the plug on this, I was wondering if I could get some advise from
anybody who might have successfully filed for a patent, created a
product, and marketed it.

ps. This plan was in motion before the virus.

Thanks.