Mine does indeed screw down onto the base, the whole whip assembly isnt that much different from any other midland cb stainless whip antenna ive seen. I compared the screw from the regular mounts and the mag mount and they are different. But mine's not midland its an Alan, very much alike though.
I looked around to see if they sold the hardware for the antenna but no luck, all I find is the regular mount one but im not paying for another antenna if I have a perfectly good one anyway, so i guess ill stick to the mag mount until I find the proper way to permanently install it