Finally had some time to get this designed.... It fits into the dash where the original speaker/ash tray went uses the same bolt holes.
[IMG]http://img185.imageshack.us/img185/6751/48to53adtruckdashinsertnq9.th.jpg[/IMG]I tried hard not to have to touch the dash, but I'll need to knock the divider out between the speaker and ash tray opening. And a small radial notch for the big gage. I'll most likely leave the metal and just move it so the dash could be restored if desired.
I could have more cut if folks were interested.