So you are afraid to play that last Doom level by yourself. Afraid you might get lost if someone doesn't hold your hand? Well, you need to stop by you friends at the Co-Op Certification Laboratory. They'll fix you right up. Their most recent mission, update some old Doom 2 levels for use in Co-op. So therefore, they now present to you Mission wads for DOOM II by Follereau Dominique (Co-op Version).
In case you're wondering, the text file accompanying the original wads grants permission to modify/reuse them. We also prominently credit the original authorThere you guys go. Enjoy. And remember to check out all the other cool stuff they have listed throughout the site.