Ok my thoughts...
On the topic of cannibalism and the death of one machine to save another, this is a hard call. I am all for getting a title I want working using a title that "sucks" in my own opinion, but that may not align with people who don't think the donor title "sucks". From a historical perspective, every time a pinball machine dies, a demon gets its wings, so breathing life into one by sucking the life out of another is not really doing the hobby many favors. I would rather see every viable machine restored to working order, but there are only a few copies of certain titles left, and without knowing it, someone may kill the last working version of a machine to restore/repair a title that has hundreds of copies still in existence. That is the downfall of cannibalism.
Now given a certain machine has no life left to give us due to blowout pf, or nearly totally flaked bg, or a cabinet that has seen dryer days, then, and only then should we consider it "dead" and it's carcass available for the vultures.
The thought of dumpsters full of old pinball machines still brings a tear to the eye...