In over my head....... HELP!!!!!!

[NSMaple1]

Truer words were never spoken. Get the original propane boiler loop back together. I know the boiler is toast, but it shouldn't be running anyway if the OWB is running. This will let you fill the system and put a static charge of 12 psi on it, which ensures that you have water all the way to the top of the building. This is why you don't have heat upstairs: your open system doesn't have enough pump to get water all the way to the second floor, and your junk manifold creates a path of least resistance through the first floor radiators for the flow that you do have. You need to create some increased resistance in the first floor circuits to create flow upstairs. Ideally, this would be done with thermostatically controlled zone valves, but you can do it by throttling manual valves, putting orifices in, or smashing the pipe (don't do that.) once you've done all that, put a heat exchanger in the loop and pipe the OWB to the other side of that. Pump that loop, and all will be well. Not really, but it will be a lot better. Look up Kevin in Ohio's install to see how it should be done.

Also the reason for my simple questions in post 38. Hard to help when the fundamentals can't be established or addressed/answered.

In order to circulate up two stories, you would need maybe 8psi at the bottom. (0.4psi/foot x maybe 16' up, plus one or two for good measure). Some pressure up top also helps keep micro bubbles in suspension & moving.

Also bleeders at the top are not needed. I have those on my system but never use them - they had a hard time getting them to stop leaking when the system was installed 20+ years ago, so no way am I touching them. Just need to hook a garden hose up to the pipes down low & power bleed them by running a bit of domestic water pressure through them to flush the air out.

The OP seems to have gone missing?