Charley

Thermal treatments will work as well, or better than pesticides in this case. If you've got freezer space, just put your mount in the freezer for 48 hours, the cold soak will kill any eggs, larva, or pupa on the mount. Heat treatment will work too. Wrap your mount in black plastic, and set it in the sun on a sunny day. get the temps up to 140 F for about two hours, and that will kill everything as well. Not too sure how the heat will affect the forms, it could damage a foam one. Check with your taxidermist.
I wouldn't recommend the total release aerosols (bug bombs). These are almost all contact kill materials, with no residual effect. They also have an oil based solvent in them that leaves a nasty oil residue on everything. When these are released, you have thousands and thousands of almost microscopic oil droplets that move around on air currents and settle out. If your pests are in a sheltered area, they will not be affected by the droplets.
I was involved in a tape and seal fumigation years ago for a guy with literally hundreds of thousands of dollars in mounts. He had dermestids (hide beetles) in some improperly tanned mounts. He had every species of deer, every antelope in the world, a dozen different bears (including a Himalayan sun bear!) all the cats, you name it. He even had a walrus mount. Never seen one before or since.