Another good source of levels for this project is the many challenges that exist for the original levels -- though please avoid repeating any that were used as talismans in Redux. Also, if you make a level based on a challenge, put "Challenge" as the author name, as it's often unclear who first originated a particular challenge.
I've updated the zip in the first post with a fix to "It's all about survival"; added "The Metal Mines"; and added three levels based on challenges:
The thing can be done! (We all fall down - 10 diggers) (talisman: 2 diggers)*
Ascending and Descending (Tribute to M.C. Escher - 100% with only builders and the floater)
A Walk on the Wild Side (Where Lemmings Dare - 100%)
* Sorry about the cheesy title. This is what I called this level in my ResEdit set when I was a kid.