One suggestion not mentioned is spectacles. Often the reason for hunching over fiddly work is to peer at it and most of us are old enough to need specs. It may well be worth getting a pair made specifically for the focal distance from work to correct stance for doing that work.
Also take care of using magnification. I owned a superbly expensive magnifying headset for fine surgical work but it really depended on keeping one's head in a narrow golden distance from the project – made the surgery easy but gave one a horrid stiff neck doing it.
pgk