I learned how to tan furs from a buckskinner (18th-cent historical reenactor) in Indiana a few years back, and practised on a variety of roadkill, from Bambi to raccoons to an unclaimed and collarless Golden Retriever. Here's the mix I use:1 gal distilled water to 1 pound non-iodized salt to 4 oz battery acid.
This makes an odorless buffered acid solution safe to dabble in with your bare hands, but strong enough to cure hides in about 3 weeks. Works between 40 degrees (F) and about 85 degrees.
Mix the salt and water in a large non-metallic tub or drum. (I usually made four gallons at a time, because that would accommodate the 16-oz containers that battery acid comes in at my local auto-parts store. Keep the empty water bottles and refill them with tap water to use as weights tokeep your furs underwater.) Slowly pour in the acid, stirring constantly -- again, with something nonmetallic like a big stick. It's exothermic at this stage. When cool, add the skins; pull them out at intervals to scrape.
When cured, rinse and spread to dry; I rub lanolin or neatsfoot oil mix in to supple them when completely dry.
By the way, a "neat" is a generic term for cattle, so this is oil extracted from the hooves and lower legs of cows.
Hope this helps/isn't too late...
Lynn