This is only a partial answer:
You could narrow down your diagnosis by comparing the volume of both heads. If both volumes match, then the new head is fine and your problem lies somewhere else.
How to measure the volume of a cylinder head.
Remove head. Attach spark plugs and valves, without rocker arms or camshafts, so that all the valves can be closed.
120 to 130 psi compression test result is within the serviceable range of a typical spark ignition combustion engine running on unleaded pump fuel.
However a spark ignition combustion engine powering a specialised machine/tool set up to run on propane with a low compression ratio will have an oil ring designed to manage engine oil that would otherwise be ...