Update:

I have it starting (warm and from cold), warms to operating temperature, with no problems.

I still don't know were the oil came from, I have ran it to temperature twice now, don't see any new oil leaking.

Questions:

Do I have a good starting low compression engine now?

Where around the oil metering pump should I look (front, bottom, connects to the block..)?

Should I premix to be sure? At what rate should I premix?

I want to save this unicorn!

Compression test will tell. No amount of arm chair diagnosing will tell you hard numbers.

Yes, everywhere the oil lines lead.

Premix is considered good practice no matter what's going on with the engine.

.5oz/gallon at every fill. And bllock the OMP as well with the RA adapter.

I'm confused as to why you're still asking about compression without actually doing a compression test?