Thanks Guys! I knew I would get plenty of advice here.
I think I am going to go with a small recirculating tank type heater, maybe switched on by a thermostat whenever the temp gets around 50f. Now I just need to figure how to plumb it. I am probably going to go with a radiator hose adaptor, and maybe the block drain, though I am leery of unscrewing anything that has been screwed in for 78 years! If I go with the block drain, should I then go to the upper or lower hose?
I know this is absurd. This thing has a delco 10si alternator and a 12v coil. The first service call I got to it was because it wouldn't start at 40f. I traced the choke cable to the firewall, got in the seat, pulled the choke, played with the accelerator and it started right up.
I was asked what that knob did, nobody there knew a vehicle could have a choke. Some training and the employees can start it right up.
Next service call, the owner couldn't remember that, so he poured the ether to it. It split the muffler wide open, BOOM! The owner "got scared" and gave up on his whole weekend's hunting and drove 75 miles home.
He wants it start and run like it's July at any time.