The decay comment on the project page is about A vs B, but there are at least three variants out there; pre-JEDEC standardization A (unbuffered), and somewhat more modern B (buffered) and UB (unbuffered). The latter two are still made, and A and UB seem suspiciously similar:
(the trailing E just means PDIP packaging)
Sam mentioned he’s ordered some UBs to test with.
EDIT: Initial UBE test results.