Thanks everyone. I dived into the engine today. Thankfully I have a nice air compressor and impact driver, stud remover and with some very thin wrenches in odd sizes.
Today I drained the old oil, removed the clutch, distributer, intake, exhaust, side cover, plugs & head. I am soaking the pistons with Marvel mystery oil (I buy it in quarts). Soaking the removable bits with penetrating oil certainly helped.
It looks like the engine is rebuild-able, even the distributer is salvageable. It has had at least some prior work in the modern magic sealer era. I expected a flat head engine would have had some work in its past. One boar looks good, two are rusty and one is a mess. I suspect that there was a leak from the cooling passages into #1 cylinder and the engine was stored tipped to the right for a long time.
I will clean up what I can then reassemble it using lots of never seize and grease before putting it away for a future rebuild.