Opening up "Demonstration" levels?
Its gone now. 
The more you give, the less appreciated it will be received.
So, was there like a real place to download that map?
Nope, people would just remake it.
Think my remake is the closest remake I ever seen. But I also counted wall panels and stuff. But also I think when Portal was in its Alpha stage I think it was using Source Engine 11, then 14. But I'm not 100% sure.
The more you give, the less appreciated it will be received.
I have this problem in my maps and I know how to fix it. Take your func_brush or movelinear or whatever the VISIBLE BRUSH for your crusher, wall, etc is. Change the option in it for generating lightmap shadows to yes.
ie: You have the crusher with an orange light above it. The light shines thru as if there was no crusher there. You click on the func_brush crusher and check generate lightmap shadows. NOTE: It only creates shadows for its starting position.
ie: You have the crusher with an orange light above it. The light shines thru as if there was no crusher there. You click on the func_brush crusher and check generate lightmap shadows. NOTE: It only creates shadows for its starting position.
The EASIEST way it to put a no draw textured brush just under the grate. Problem solved
Edit: also you can rescale the orange texture to 50x 50y to get rid of it's light (just like the white textures)
Actually, I found out that in the crusher demonstration level, there was no orange light at all. I removed the orange light and looks like the level.
Besides, I just redid the map. . . . lol
The more you give, the less appreciated it will be received.