Hi Mark ...
The CPO on my panel is 22.25" wide (it is not corner to corner) ... pic attached.
I've also attached the bottom pic which you have already seen so we can talk about the mounting of the stick. I haven't taken the panel apart yet (I only just got it), but it looks to me as if the wood portion comes off (carriage bolts at the four corners and centred on either side of the stick) and the stick is top-mounted into the wood portion of the panel (4 bolts to the left and right of the stick).
I dug through my arcade files and found the stencil graphics that I spoke of -- they are fullsize GIFs (one for each of blue, red and black). Stupidly, it seems that I did not grab the kickplate stencils and have been unable to find the site I downloaded them from originally. I'll keep looking. I do have the sideart and kickplate art in fullsize GIF (at 96 DPI) as well if that is of interest.
Well, I'd best get back to work.
Cheers.