halfhack, I have a suggestion; for I too have looked at some of the mapping in Half-Life and been impressed with how ahead of it's time it was (the thing's
old, remember).
so you should have the halflife.wad right? look at a particular map, say... c1a3 (a classic), and try and re-create it, changing things you wanted to change as you go, it will be good practice for all the little tricks they used. swinging lights/elevators/ambient effects/etc.
don't just get lazy and try to rip someone elses stuff off (i understand you only want to change a few things and will
never release the modified map - that wasn't a request, that was an order!
, but you won't learn by doing what you want to do, you'll simply get lazier)
so good luck recreating those maps, and don't show them to us when they're done lol. I would never want to rip off Valve, they have screwed up alot over the last year or two, but they're good guys at heart
ps. if you can't be bothered to search the forums for coolfat's post about ripping maps i can't be arsed to explain again