Cylinder head tests OK, about.004" out of level diagonally across combustion deck. Machine shop going to do valve job and 1 spark plug thread insert (#4 cyl). All this was arranged Tuesday. Still no response from Cometic Gasket after a week since I sent them a query using their website contact facility.

Now for the report on the block and pistons.
All 4 pistons show some heavy scratching and signs of slight galling on the skirt thrust side. The cylinders themselves show scratching bad enough that you can just barely feel the scratches when dragging a fingernail across.
Cylinders are from.003" to.005" worn on taper.
Pistons worn down about the same average amounts (.003" to.005").
Piston top rings were placed into the cylinders and end gap checked. The least end gap was measured at about.035" and the most was near to.048". Specs for ring end gap of top and second ring on this engine are.011" to.020". Like Neil Young once said in a song, "That hound dog is history."
My local engine parts warehouse is unable to find any info about pistons for this engine and alluded that if I came up with a GM part number they might be able to search for it as a cross ref.
The only source of part numbers we have is Tennant, and Tennant has adopted the practice of assigning a Tennant part number to everything they sell. Tennant price for a single piston kit (piston, pin, and rings) is $136 USD.

I went back through my notes and realized that I had omitted Helmar from the list of potentials I gave my boss when we first decided to replace the engine with a new one.
He contacted Helmar and Helmar said our new engine would arrive at our location within 14 business days.
Thanks Partsguy5.