Okay so I'm ready for a status update. I've done some listening (perhaps not well enough), but I do believe it's an improvement...
Mouse Buttons I'm glad to hear I can map them to something else, and I like the idea of the P1 P2 buttons for brief use in the OS.
Admin Buttons I can always add them on the side later, right?

The one thing I'm really having a hard time getting my head around is moving the 4-way stick on the front lines. I just don't think I can push myself to break the symmetry to the point that I might have to move the trackball, loose free space, or expand the panel. I
have moved it around some and sacrificed a bit of symmetry in the process, but maybe I'm too hung up on the appearance still. I do feel like at least the panel will be roomy at 36" x17"; Isn't that large for most 2 player panels?
There is something I failed to mention earlier. I'm planning on building this as a sort of free standing control panel on a stand which I will have to build; basically like the CP of a showcase cab. People will be able to play Golden Tee as clumsily as they like without hitting anything, so long as they don't aim their thumb at the 4-way. I doubt this has much bearing on where buttons go on the panel, but I figure it's worth mentioning just in case.
Attached are the current layout with mounting brackets, as well as a simulated view of the final appearance before artwork.
I really appreciate the feedback and I have the utmost respect for all of your opinions. Please feel free to let me know what you think of the latest version. I'm anxious to send the mounting placement off to print so I can get started on fabrication.
