Hello,
I personally have no problem with cleaning up restorations.
If one hopes to make a satisfactory enlargement of a smaller retouched print, it is often necessary to do what ever you have to do to deliver a quality product. If it is an item of historical value, make a copy negitave and work from that, never the original. Do nothing to an original negative that cannot be undone if necessary. I personally would never alter in anyway a customers negative or glass plate. I heavily recommend using a copy work negative.
For me the same goes for any print, I will not work on an
original negative or print without a copy negative of it and a good work print.
Charlie........................................