Here are some pics of the interior patch pieces. I quickly made a cardboard template, used a hole saw to cut a hole in it for the roll bar and used tin snips so I could bend the panel to fit around the roll bar, then bent it back and plug welded it in place.
Some small updates today, literally. No small amount of work, though. I noticed that when I put my roll bar in it interfered with where the dome light would go, and since I took the roof support out the dome light mount came out as well so I took this time to relocate it. I ended up chopping it out, moving it back, and adding some filler material before reinstalling the roof support. I also made some plates to fill in the unsightly holes in the floor I made while installing the roll bar.
Today I finished up fitting the pass down tube, made some gussets with smaller diameter DOM tubing, and welded it all in. I had an "aw crap" moment when I realized that my cage fit so tight that I couldn't slide my bars forward enough to lower them to weld the top halves. To solve this I had to remove the support that runs across the roof panel. Glad that was only spot welded at the ends and not along the roof itself. I did make 2 slight positive bumps in my roof moving the cage forward, oh well. I'll see if I can tap them back down at a later point. I also rattle canned the bars to minimize flash rusting. At a later point I'll add a bar that runs across the main hoop for mounting seatbelts after I get seats, mount them and all that. Same for adding angled tubing from that point to the frame rail itself. In the meantime I will add a few attachments to the body to stiffen the body, and a few more gussets, too.