I too have been trying a long time to get Some Variant of GLQuake to work on my CSPPC + Prometheus/Voodoo 3 3000 combo.
Quake 2 works great but it's the original I really want to play, GLQuake from Soft3dev grey screens and Blitzquake 68k works, but Blitzquake WOS always says it can't load GFX.wad, and snoopdos only reports a fail on looking for pak2.pak.
Robert