My rule is to
pull anything that looks different or interesting. Obviously
a 16-256k logic board is worth preserving, but so are any special looking
^^^^^^^
Presumably you mean a 16-64K logic board here. That was the first IBM PC
motherboard and is thus historically interesting. The later 64-256K board
is a lot more common, though :-(
Was it really "later", or was the 64-256k an option available at the same
time as the 16-64k?