I have bought a 7202 19" WG and measuring w/the included fram is 20.5 inches.
I think the idea that you are thinking could be done but very very close. I have a 19" cab with this 19" Monitors and looking at it, really really close. Take a look at my setup in the Project/announcement section (search for Arcademania) if interested in haveing Dual Monitor Setup in your 19"Cabinet (just like mine). Easy to do and no rotating involve, it only involve flick of a switch.