Yohoat you barely have a functioning grasp of how Hammer or Source works. I am genuinely afraid of what a "mod" made by you is going to look like.

What do you mean? I don't understand why you say I don't understand hammer or source.

This would have to be carefully thought out not just replace textures.

Waiting for a reply msleeper...

I think this is actually a reasonable idea, so long as those involved know what they're doing.

I've actually done this already.
I just copied all the files and maps from portal 1 to portal 2.
It loaded surprisingly fast compared to the portal 1 engine.

There were some missing textures still, and some of the scripts were broken for GLaDOS, but it's all there.
Barely any work at all if someone wants to go through and fix up the scripts and textures.
Maybe even update the textures to portal 2?

I was thinking not just copy and paste. More along the lines of revamping with the portal 2 style.