I think it could use an angled area below the marquee for speakers, once you find out how much space the TV is going to take up.
Unless the TV is going to be set way above where the back of the CP is, you are probably going to end up with alot of dead space along the bottom of the marquee, between the marquee and the monitor bezel.
My cab dimensions are pretty close to yours.
Here's what I did on mine.
Unfinished CabMy cab's changed alot since then, but you can BARELY see the speaker area above.
It's angled at about 30 degrees.
That way it keep the speakers a little less visible than on some of the original cabs I've seen, but eats up what would have been a BIG dead space on the run back to the monitor bezel.
You might also want to pull the bottom curve up to just under the bottom of the CP if you're going to install a coin door.
If you don't, the coin door will be right in your face while playing.
Well, not LITERALLY, but you get the idea.
The only other question I would have is whether the CP box is deep enough for the controls you are going to put in it.
I can't read the dimensions on the drawing, so be sure you double-check before you commit the design to wood.