Frame question - ceiling under skin

[Kidkraz]

I don't know that this pic can help, but I wanted to post in case it could. I don't remember where I found it, on this forum or elsewhere. Its not a great picture, but it does give a view on how that cabinet fits on the front shell and you can kinda see there's some wood to screw into the corners. I had a minor water leak and dropped my cab, but reinstalled it using the same holes.
Found that its from an member Maria, she had a blog on repairing an old TM.