Finally finished the back yard renovation that has kept me busy for a couple of months, so getting back to Joker Poker now, and with the temperature up, painting can get done.
This cabinet had what seemed to be an issue with the second layer of ply. It was extremely soft. I replaced the back as I wanted to take a good look at the wood to ensure there was nothing going on. On examination, seemed just a very soft layer of wood.
The issue is caused however, was the edges rounded off quite a lot at the base of the cabinet. I could have beveled them and it would have been OK, but the OCD in me forced me to carefully cut out the edge, and splice in some hardwood strips so that I had a nice edge. Didn't take as much effort as I expected, but still a fair bit of time, but now that I have some primer on it this morning and can see the nice new edge, pretty happy I did it.
Here it is after the cutting. The second photo show the piece to be glued in place shortly.