I never put one up before. So I tried fleshing one and man did I destroy it. How much should you take off? Just the lose meat and fat and leave the rest?

You do not want to over flesh.The main pockets of fat are below the front legs and along the bottom.
I use a one handled flesher and remove most of the attached meat and fat.
Tom

I think that was what I did. So mainly just get the loose stuff and let the rest dry down? My is putting up Beaver. I ripped a hole in the belly of that rat that you could put your fist throught and it happen so quick and easy.

I hope you caught the muskrat in another state flatiron, because the season does not come in until the 22nd here in PA

Just remove the loose fat & meat and the same with mink, don't try to flesh them down to the skin. They look & feel a whole lot better.

Trapperob

This was A rat in my freezer from last year. I was trying to make room for coon hides and come across it. This year I decided to put everything up and sell it at auction after seeing my check last year for just Beaver hides

You have to leave the saddle on muskrats. It's the red membrane thing. Sometimes there's fat under it, just squeeze it out of there with force, but leave the membrane. Muskrats have thin skins, and it's no good for garment making being too thin without the saddle. Rats are kind of like squirrel, you can flesh them with a big spoon.