If you find yourself needing to tan another snakeskin hide, try tacking it to a board and then coating the flesh side with salt. Let it cure, then rub the salt off and coat the skin with glycerin.
P.S.- Why keep the rattle in an alcohol solution?
Ok, I'll try that next time. Because I whacked off the whole end of his tail and threw it all in there. Alcohol (93% rubbing) works pretty well to preserve things. I have a few snake heads, and some bugs preserved in it.