oho someone to dig this thread from its grave
well SF, since you "wish I had", then now I ask you, officially, to do something potable with it.
Don't believe it's too much for this engine : we just don't run HL/CS on the same computers nowadays than in 1998 when it was out
And also I have a lotta ideas to cut down the brushes count. With an extensive usage of sprites and transparent textures, I'm sure I would make something enjoyable if days lasted 48 hours instead of 24.
For example, I could replace all the windows with sprites ; idem for all the barriers on the upper floor.
I could also create custom models and replace brushes with them: the arches, the pillars, or the wood under the roof. The problem is only the interior of the cathedral anyway.