Very interesting about the Apple-branded DRAMs exhibiting unusually high incidence of bit rot. I've not seen that myself, but your data certainly trumps my non-data. I'm just trying to figure out how two could fail together (assuming that this is what happened), or what type of failure of one DRAM could cause the death of another.

It is true that US memory manufacturers didn't do such a great job of manufacturing and testing DRAMs back in the 80s (which is why we got our backsides kicked by the Japanese). Perhaps you're seeing the longer-term consequences of poor QA/QC.

In any case, I'm glad that the OP got it working -- it's nice when a compact Mac is saved from the scrap heap!