If I was not wanting to mount my skinner base to my concrete floor so it could be moved out of the way after season how much weight should it be attached to so the winch would not pick it up and still be able to pull the hide

Use in floor anchors, when you remove it for summer, screw the bolts down into the anchors to keep dirt out.

I have not decided how mine will b e fastened yet. a trapping friend who has a system he made that is at an angle due to ceiling height. mounted his base to a 7 foot 1 by 10 hardwood board. He buys about 10 bags of water softener and lays those on the board. He uses those softener bags up during the year and re-supplies every fall.

Bryce

A used tractor wheel weight would work well if you can find one.

Put a kicker on it, and mount to the wall at the floor.

x2
I use cement floor anchors and only use two bolts. I remove in the off season, and cover anchor holes with duct tape to keep dirt out.

You can build a angle Iron H frame that will just sit on the floor. Then you can mount your Skinner to that. If the four legs would stick out about 3 feet front and back and they are about 3 feet between them you should be good to go.
Like Hern said I use concrete anchors to anchor mine In place.

I prefer to mount mine to the wall so it can swivel up against the wall out of the way when not in use. I understand not wanting to drill into your concrete. The other option would be building a frame like Beav mentioned. Weights under the base are a huge pain and will raise your base too high so when you get to the head, you'll barely be able to reach it on a big coyote. Plus the weights get covered in blood and nasty stuff that sucks to clean up.

Check out Coon Creek Outdoors youtube videos,he recently went to a contest winners who used a pail full of concrete for his temporary base-you can get n idea of what to use from that

I bolt mine to the floor and when it is not in use I put set screws in the holes to keep dirt out. A little anti-seize on the threads helps with easy removal.