On a friends' recommendation gave some heads to a taxidermist who is fairly close, and seems to do reasonable work, cheap and quick.
The thing that amazed me is that he was able to turn around a head in just over a month.
I asked him what he used for tanning and his answer was somewhat vague, being basically one part alume and potassium hydroxide and two parts salt with acid, possibly phosphoric to a ph level of 4 or 5.

Now I have doubts as to the longevity of the mounts. His work turned out to be mediocre and I have stopped giving him work, though I still have several heads there now...

Can anyone tell me if the tanning solution he mentions sounds right?

Not with a ten foot pole. Visited another local taxi who does wet tanning and -- his place absolutely reeked. Almost threw up, and I don't mean from goat smell. If the tanned skins don't smell nice and lemony like from Victoria (South Texas Fur Dressers)...

No it wasn't Tim's, and Bruce Gotcher does my stuff.

I live about two hours from Victoria. Sixteen months ago I took a coyote skin to my local taxidermists that has done work for me in the past. He said he sent it to Victoria for the tanning. Want to make a coyote skin cap from it. I am beginning there is something fishy. I still haven't gotten my hide back yet.