UPDATE

I forgot to update this thread with details on the MEMTEST86 results.
https://i.postimg.cc/gc5kc7FP/memtest01.jpg

The old BIOS PC runs for days on end, but sometimes randomly BSODs.
o Yet, I almost never fail to solve such problems, so I'm still at it.

As per n/a's suggestions, I ran a bunch of memtest86 test configurations:
https://i.postimg.cc/KY1Yk4WP/memtest02.jpg

All reported the memory to be just fine so I need advice on more tests!
o What PC hardware diagnostic stress-testing freeware can you recommend?
https://groups.google.com/forum/#!topic/alt.comp.microsoft.windows/a6aAvxnDRB8
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