I have been doing alot of taxidermy work with real skulls as well as homemade form molded and retail reproduction skulls.
I have had the best luck with a couple from the Wasko Catalog.
1- the Pinchback skulls
2- the Hinton reproduction skulls
I use a dremel to carve out as much of the repro's as possible for realism, using a real skull as a template.
there are 2 trains of thought to go along with these skulls. with or without pedicals. without pedicals you mount the skull plate into place with bondo and newpaper or fiberglass filling and screws. then paint to correct.
I have come to the point of using the pedical models and using the Small, Medium or Large skulls and using pictures to correct the width, angles and side of the bone structure with Fixit epoxy, then use a small amount of paint to correct. I think over time, this is the way to go, since you dont have to worry about any issues with the skull plate later on.
I dremel out the the inside of the pedicals. cut off the skull plate at the antler, drill a small hole to epoxy a hex bolt into the antler base and then using a pic for a guideline mix 2 part epoxy into the hollowed out pedicals and set both the antlers into the pedicals and use the picture as a reference.
the ones I have done this way have turned out great, solid and worry free. in reality it is very simple to do. spray the skull down with a poly or another coating and it will leave a hint of yellow to the skull for realism.
If you have several skulls, I found that you really want them all to look the same. there is so much difference in all the possible repro skulls, they looked odd on the wall and I have actually taken antlers off of some skulls and replaced them unto other skulls.
good luck.