15' Keystone Hideout 28BHS - rear bumper attachment

I recently took the tire and mount off of my Salem Hemisphere Lite 282RK because I wanted to move some weight forward (rear kitchen = heavy in the back). The tire and mount I removed is about 65lbs and had U-bolts holding it to the bumper which is identical to Keystone's. (I used to have a Springdale 256RLLS)