I say no to the forum. I own a W124, and I suppose it could be nice to have a W124 specific forum. However, we already have quite a large number of forums to read. What could we possibly need a forum specific to W124s for? It is not difficult to find information using the search feature, and most every W124 problem can be posted in the Tech Help forum.
1976 300D (W115) - 330K and still going (sort of)
1991 300D 2.5 Turbo - Sold at 221K
1983 280SEL - Sold at 206K
1981 300SD - Sold at 232K