I know the collector's book on the insulators is titled "Jewels of the Wire", but don't remember any specific collectors club.
You might try a Google search. If they have a newletter or ezine for the members, you could see about placing an ad. At the same time, someone with a serious collection could probably give you a current market value on them before you modify all of them.
Some purists want their jewels as original as possible.
A classier way of displaying them is as a pen dest set. You cut a nice board from walnut, oak, or other attractive wood, attach one of the screw mount pieces to hold the insulator on one side and a pen and pen mount on the other. They can then be taken to "Things Remembered" or a trophy shop to have a personalized nameplate added. (A serious collector can point you in the right direction to find some original or reproduction screw mounts.
Would that Katy RR have run to or through Houston?
Dennis Bevers
What I do when not reading and posting on 7 different forums!