I seem to remember that someone on this forum refinishes
refractometer hemicylinders. I was unable to find anything in the
archives. Anyone remember who that was or are you out there? I have
one that is a bit pitted and scratched up and needs your services!
Dave-- Try the good old GIA-- their Gem Instruments division used to
do hemicylinder refinishing, seems like it was about $75 or so. And
they do a perfect job, recalibrate the instrument, etc.