One reason mounts take several months is because many taxidermists send their capes to a tannery. They won't get the capes back for a couple months.
Now if the taxi does his own tanning it can be done quickly. There are many home tans out there. Krowtan, McKenzie tan, John Rinehart Tanning solution, and many others.
Heck once the cape is tanned, it doesn't take that long to put the mount together then the rest of the time is drying time.