Lets me reveal the secret behind my Happy New Year post.
Some people suspected that it was a joke. Some suspected its been a nice hack. But seems nobody tried to use one of the search machines.
The main work was neither to create the three levels nor to patch them into the ROM. The main work was to change the Level Codes. Unexpected, isnt it?
There is a large community supporting Chips Challenge... but not for the Lynx. There exists an active(!) community which created not only level editors but thousands of levels and the utilities to convert them in a format to be run my the M$DOS version of CC ... and the Lynx version. This was actually done YEARS ago by Brian Raiter. As a starting point a few links:
Tile World, c4: http://www.muppetlabs.com/~breadbox/software/tworld/
Newsgroup: http://chips.kaseorg.com/newsgroup/
Forums: http://cczone.invisionzone.com/
If you like to read a bit about how to patch existing ROMs, you can find the story in the usual location, including a script which enhances the original script by some nice features (like level codes). Have phun creating your own ROMs.