I'm another one that likes to fly under the radar..
I used to work in a shop that the owner thought it would be
a good idea to run a small ad in the yellow pages.. What
a waste of time and money.. CONSTANT calls, CONSTANT!!
Can you resurface the head on my toyota. No we aren't
that kind of machine shop.. Well what else does a machine
shop do?? All day everyday, automotive calls..
And then the inventors.. There have been a few that understood
and knew that it wasn't going to be free, but most assumed
that it cost literally nothing to make prototype parts...
And most wanted you to do all the design work for them..
And farmers.. Farmers are a pain in the ass, they are CHEAP!!!!
Their stuff is always dirty, oily, disgusting and rusted, and so
far beyond functional that reverse engineering can be a trick...
Knock on doors and network.. Make sure everybody knows what you do.
If your wife has an afterwork function (aka PARTY), make sure you go,
and talk to everybody.. Join the local model railroad club, historical
society, old car club, model aviation club....
I met my favorite customer in a bar.. A lot of trades guys go
there in the afternoon, and they know EVERYBODY..
And knock on some doors.. I made a decent chunk of change making parts
for outdated printing machines at an independent office supply/printing
company.
There was even a deli that was fun to do work for, never a lot of money,
a $100 here, $60 there, but every time we fixed something for the guy,
he would always come just before lunch time with cash and a giant
party sub, sodas and sides, enough to feed the shop for lunch, and
leftovers for the afternoon evening guys..
I know talking to people sucks, but its something you have to do..
EDIT: After saying all that, just make your own product(s), and not
have to deal with any of that.