. Yes, I'm planning on running the test you mentioned, and I really appreciate the technical advice. I just don't want to "throw good money after bad" as the old saying goes.
a leakdown tester is 80bux at harbor freight, compression tester is 30, and a vacuum gauge is 15. or a lot of parts store "rent them".
i'd consider those tools an investment. and you'd have a lot of your questions answered and be able to move forward with a better idea of which way you want to go.