Hello Al, welcome to the forum.
first, a question: is your unit a Furnace [makes hot air] or a boiler? which makes hot water??
I'm afraid you may have to roll up your sleeves and get dirty,, like you said, burning coal is a lost art, and even in the east where coal was very common,
there are not a lot of good repairmen anymore,
Do a google search for Pease Feed and hardware, ro variations on Pease, Combsutioneer, Stokermatic. There used to be a retailer and repair
company that was something Pease they had a lot of parts and info about Bituminous and Sub Bit burning units. they were located in Wyoming or montana..
I'll try a search and see what i can find.
If you can post a few photos of the units, both the stoker and the whole setup,, with name and number plates if you can.
Stay warm @@