@Michael,

"... and found the original tube of PALCE16V8 GALs that I purchased in 1995 so I could make new parts for the customer."


I fear, there is no great success on reusing the same old charge, which was already detected as faulty.
You should better use today PALCE or GAL16V8 devices.

On a German forum I found also an interesting thread, that a typical plastics case was not waterproofed.

E.g. the Maxim DS1820 temperature sensor can have over 3°C deviation, if they getting wet (I tested it already). The deviation disappears after heating some hours.


Peter