Theoretically that would work; the trouble is that it would be wildly impractical. The 2114 is only 4 bits wide, and so you would have to create a daughter board with pins which perfectly line up with both of the 2114 chips, and then run the address, power and control lines to both chips, while running half of the data lines to each chip separately. That also assumes that there is, as you mentioned, enough room inside the meter's case for the additional board, and the new RAM chip.
Instead of worrying about spacing, just use an 8 bit RAM to replace each 2114
I haven't decided either way,
First, I'd probably replace the faulty rams with used but known working direct replacements to make sure that was the fault and see if the 100 point data-logging is then working reliable.
Secondly, how long will 30 year old, used ram chips last?
Doing a mod to more modern chips might be worth the hassle in the end, so any suggestions for those is much appreciated.
Or is it a good time to learn arduino and use that?
I'm not to worried about hacking some hardware together, but haven't done any digital designs and programming apart
from turbo pascal and some basic shift registers etc. over twenty years ago..
time flies when you're getting old(-er).
So any tips and pointers there are also much appreciated.