The problem with a site just for w124 is that the volume of trafic won't get people like me to spend their time there. I am involved with 5 auto related sites; four of them very specific technician oriented sites.
This site is the only one that I participate in that allows questions from consumers/DIYers. To me all MBs are special and my interest is in making strong sites for mutuel benefit. I can't tell you how much I've learned from every site I am involved with including this one. My time is limited though and I would likely not wish to dilute my efforts.
BTW since I'm discussing myself, I just wrote the cover article for "Import Car" a trade publication. Titled: Mercedes-Benz: A/C Control Diagnostics.
Here is a link to the article, it provides the bulk of the diagnostics for a technician to diagnose half of the A/C questions asked on this forum. I gathered a number of my Mercedesshop.com replies as a basis for the text. The photos and scope captures were especially gratifying to me as they were techniques and software that I had learned mostly from the internet. Doing the article made me finish my project to be able to capture screen prints from my Bosch engine analyzer/DSO. here is the link:
You have to click on Import Car as I can't seem to get the whole link.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician