I hesitate to comment because I have had mine replaced once already and I know the replacement came out of a gwagen but didn't look anything like the original (wildly different line routing).  In fact this is somewhat timely because the replacement just died a few weeks ago, now I get roughly 250km (~24l/100km or ~10mpg) down from around 350km to the tank.  My mechanic is actively looking at alternate warmup regulators from old mechanically injected mercedes cars trying to see if he can find a good one since last I looked mercedes wanted about 1000ish for a new gwagen one.

    Chris.

Mine has a vacuum line to it, as well as the two fuel lines.  I don't know whether the presence of teh vac line is the only indicator of a full load enrichment feature, but mine does have the vac line.

Hey Chris,  for a grand I'll sell you a WUC with the whole M110 attached!

-Dave G.