I worked with some green (fresh) cow hides when I was younger. The one that turned out best was not salted or treated with anything, except for washing it with Octagon soap. I fleshed it carefully and stretched it on a frame to dry. Once dry, I just scraped the hair off, which was easier than you might think.
I know the OP wants to clear out his freezer. If that moose hide were mine, I would take it out and let it thaw, and then spread it out. I would hose off the salt, wash the flesh side with Ivory or Octagon soap, and then trim the edges, cutting it down to a neat rectangle or trapezoid shape. One thing I learned years ago was that trying to flesh all those little tags and the ends of the legs was tedious and time consuming. They also make it harder to stretch the hide in a frame. The hide is thinner out toward the edges, and the odd shaped little tags are pretty worthless as rawhide or leather, anyway. A regular shape with straight sides does not really waste anything useful, and is a lot easier to deal with.
After the salt has been removed and the hide has been trimmed to a size and shape you can handle, stretch it on a frame and let it dry. Even if it hasn't been fleshed, whatever tissue is on there has probably been "freeze dried" by now, and it isn't likely to spoil. You can just leave the hide in the frame until you are ready to work with it.
The commercial buffalo hunters of the 1870's did not salt or even flesh the hides of the animals they killed. The skins were simply taken off the animals and "pegged out," hair side down, to dry in the open. Once dried, the hides could be stacked like sheets of plywood.
Plains Indians didn't salt buffalo hides, either. It just wasn't feasible for nomadic people to carry around the quantities of salt that would be required. In working with green hides, I found that salted hides tended to dry "flint hard," while unsalted raw hides were more flexible when dried.
Again, if I were anywhere close, I would pick this hide up. Four cheap two-by-fours, a handful of spikes, and a fifty-foot hank of 3/16" or 1/4" nylon rope is all you need for stretching the hide on a frame. Invest a couple of hours in washing, trimming, and stretching the hide, and it will keep indefinitely. You can finish fleshing and dehairing the hide when you find time.
Best regards,
Notchy Bob
