Just a thought, if you are looking for something that is antler-ish in looks, consider some manzanita driftwood. It tends to be relatively thin & branchy...in fact when I try to describe it to people, I often tell them that the branchier pieces look a lot like a deer's antlers. You can usually find some on aquarium auction sites like Aquabid, or you can buy it online. I currently have an order in with manzanita.com. I haven't gotten it in yet so I can't say anything about the quality of their wood quite yet, but I can tell you that the guy in charge (Rich) is helpful, friendly and very willing to work with you to put together an order that will fit your tank size and match what you are looking for. I've known other people who have ordered from him before and all of them have had nothing but positive things to say about his company and the wood they got from him.
As for using an actual antler, as long as it was thoroughly cleaned, sterilized, and well-dried out, I would think it would be fine--again, with the recognition it will leach calcium etc. into the water, gradually increasing the hardness and probably the pH. Whether that is a negative for you or not depends upon what you are keeping in your tank and what the current water chemistry of your tankwater is.
