To include reptiles. On snakes this is what I recommend.
*On thin skinned snakes (rattlesnakes, colubrids, etc..):
Cut the snake down the belly with scissors. Try to keep in the center. After that you can just use your fingers and separate the skin from the carcass. It will actually just peel away by pulling. YOU MUST FLESH IT next. I use a taxidermy tool called a fish skinning knife. It is serrated (sp). Not sharp. Do not use a sharp knife or scalpel to flesh. I also use a dry preservative (powder) and sprinkle it heavy on the flesh side and use the fish skinning tool. The powder helps the tool grab the flesh. I then start at the head and work towards the tail, also starting in the center and scraping towards the outside. If it is too slimy, add more dry preserve to grab the meat. IF YOU DECIDE TO SKIP THIS STEP, YOUR SKIN WILL ROT. I then wash the skin by hand in the sink with dish wash soap to get all the dry preserve off (if not it will stain it white). I then tack it down with the flesh side up on a board, and I put the board at a 45 degree angle. I mix 1:1 equal parts of glycerine and rubbing alcohol. You have to really shake it up. I then use a small paint brush or tooth brush to brush the mixture on. The alcohol acts as a travel agent into the skin and takes the glycerine with it, then the alcohol evaporates, leaving the glycerine (softening agent) in the skin. The first coat will dry within a few hours. Just add another coat, wait for it to dry. Soon the skin won't dry between coats (it can't take anymore). Wipe off the excess glycerine and the snake skin should last forever. Do not wash it with water after that as the water will dilute the glycerine real fast. I have skins that I did in 1982 that are soft as can be.
*Thick skinned snakes (pythons, etc...):
Do everything the same, EXCEPT after fleshing and washing you will need to soak the skin in a degreaser. Taxidermy companies sell commercial degreasers or you can use white gas. I would soak the skin for a couple of days, take out and wash with dish washing liquid before using the glycerine/alcohol.
Your mold is not good. I would recommend fleshing the meat that is still on your skin and then degrease it. You might lose it as it sounds like bacteria as already set in.
Good luck.
Kerby...
Taxidermy pics