Of course, keeping the reproduction parts to a minimum
is still desirable, and
logging any non-original parts that have been used seems like a very good idea...
I would also suggest keeping any compoents that were removed with the
machine (e.g. if you replace a chip,. stick the old one in bag inside the
machine, in a box with the log book, whatever). This applies, of course,
only to rare/significant machines, it's not necessary for people
repairing Apple ][+'s :-)
-tony