I actually did not do the loin's share of the work for the meet up. That was Bill (bkpagoda). We did all meet because of my very long email list of Classic Mercedes cars in the area. I know there is usually a similar deal in California with 113s. It isn't that difficult to do. You just start by posting an event on this site and let owners in the area respond. I think there is also a way to do a member search by city or state. You can also use the regional MBCA club to get names as well. Most sections are hungry for events with Classic Mercedes.
Takes a little time to get started but is well worth it. I have met a lot of amazing Mercedes people in the process.
