Good luck on your next posting.
First question: where are you (and the gear) now? That has a lot to
do with what things will go for, and how easily.
Second question: how much time do you have to deal with it? Less
Once upon a time, many of the larger posts had crafts programs
through the morale office. I don't know what the situation is these
days, but if you get to the 'gotta go' stage, you might look into
whether or not there still is such a program and if the morale
office wants the gear. (Tax donation?) At least you know it'll be
used by the deserving.
As far as selling it, ebay and craigslist are the two classic
A better strategy might be to talk to your grandfather's friends.
Rockhounds do not exist in a vacuum. They have buddies. Buddies who
might want the gear, or at very least, might know the local lapidary
hobbyists, and know if there are any young ones who would want the
gear. Find the local lapidary club, and see what they can do to
help. Nobody really wants to see stuff end up on ebay, so they may be
able to assist.
Hope this helps,