nice work but you'll need to make the access hole larger to get the body bushing and bolt through that hole, that is unless you are using something else as an alternative to a body bushing.
The bushings wont go though that hole for sure. Actually we took an electrical fish tape and ran it down to the next hole where the front of the frame and the sides come together and pulled one into place from there with the mock up plate held on with clamps. We put the hole in there (there is a factory one on the outside of the frame too) so we could maneuver everything into place once we pulled it through. Once we knew we could do it we welded it up.
good catch