Yes, the W201 got that vent earlier than the W124. I saw a 190D 2.5 Turbo in a parking lot just last weekend that was in incredible condition.
Anyway, thanks for correcting me Jim. You're certainly right about no vent on the 87 300TD. But now you've really got me wondering. Wasn't the gray market pretty much dried up by the time the W124 was introduced? Maybe the owner of the wagon in question had the right front quarter panel replaced with one from a later year.