After i looked into what it takes to do a compression test, i decided i don't want to risk doing more damage by running the engine. plus it is a bunch of work to put things back together and do it, and it may not tell me enough. So i will pull the head off so i can look at the valves. I am travelling around this weekend, so it will be the next.I would not warm the engine up to do a test.
And if the engine is binding, I am not sure would start it up as you already have identified the buzzing mechanism. Just get stuck into getting the head off while it and the pistons are most likely sound.
The rods can fail due to the buzzing.
Whether they magnaflux them. or how exactly they are tested I am not sure... But test them.
Hm, i better change my location - i dont live in detroit anymore.