Amazingly I finally got X (3.3.6) to work on my 7500. All I did was use an altered version of an XF86Config file from my LinuxPPC install. I also used the xservers they supply with their distribution: xpmac and XFree68_FBDev.
Both xpmac and XFree68_FBDev work, but for some reason I have no mouse support on my xpmac. XFree68_FBDev is somewhat fuzzy, but it has a mouse. So what do you think is wrong with the potato binary of X 3.3.6 shipped with Debian powerpc? Could you recall what you did to get Debian's X binary to run on on your 7500? Thanks, -- wcrowshaw