freeze drying is pretty expensive and time consumming, but it works good. One other alternitive you did not mention is getting actificail velvet on it, then you never have to worry about it. and it is not exactly formeldehyde, that most of use, but one way it to drill a hole up through the skull plate into the base of each antler, then attache a copper fitting to your garden hose that will fit snuggle in the hole that you drilled, then take a needle and poke a million holes in the velvet, escpecially out on the ends were they are really soft, then turn on your hose and insert into the hole you drilled, this will force clean water up through the antler and blood will come out all of the little needle holes you made, keep doing this unitil just clean water comes out the holes. Then their are lots of ways to get it dried out, take a syringe and inject salt water all over underneath the velvet, "paint" the outside with lacuar thinner, several times a day for a few days, ect...ect...ect...BUt they key is to get out all of the blood first....hope this helps.
