I didn't download it yet but what does this do ?
Reskin some models?
Its pretty much a reskin, yes, a few things are different such as the ones in the pics, I removed most prop reskins as they broke a lot of how levels looked, I also removed materials/models because most of them didnt work right seeing a retail uses different models, I made tweak it more, I mostly made it for personal use but felt like sharing it.
Any one can do this too, like I said I litterly took the materials folder from anon-hl2/hl2/materials
and threw it into steamapps/common/hl2/hl2/custom