We Have a Ton of old Whitetail racks laying around. You can Buy a Skull mount on amazon but figured we could Remix a skull. With some cutting and adding some holes we have the same basic mount. I adjusted some of the holes from the original and have yet to print this profile, but should work fine. The screw holes are not perfect and wont matter your antlers wont be either. As this is a scan of a White Tail skull it will also only be symmetrical to that deer. But all in all, any horns will look good. Some Screws and some good glue and your set..Happy Printing. Feel free to adjust all you need..  FYI we are not experts, lol, but turned out good. Our test was a smaller rack, Time for the Big guys!!!!

Edited. Added extra build plate with a different skull cap, added Sinus holes, 

Step 1) Cut your antlers as close to where they mushroom. On the bone not Antler.  Make the cut level and even, you may have to sand it a little for better contact.

Step 2) Find close to center of Bone and drill holes for your screw size you choose. screws are nothing special, Id say a 2 inch drywall scew would work, But really what ever you decide. Holes are 6mm.

Step 3)screw antlers to skull cap piece, You can measure what you spread of the rack was and get close. I used a dab of glue for each hole including the screw. With normal gorilla glue you have some working time. Attach them semi tight. Measure them make sure you have them where you want them, because they will rotate and can be adjusted in or out by turning. when they are where you need them, snug up scews.

step 4) Spread glue on skull cap and main body and glue together. Sorry about the tight fit. Line up pegs may take some work t get them started. As you can see I used clamps and a good amount of glue. I wiped what spilled out aft it clamped it..