Hey sjc.
That would indeed be the water pump. Write it up with some pics to help out your fellow 210-iacs.
JMHO but the recommendation would be to buy meaningful parts from trusted sources such as autohausaz or germanstar and not from ebay.
Take care and enjoy the ride,
Greg
Hey guys I just did the water pump on my 98 320. I can't stress enough the IMPORTANCE of using the right tools!!. I purchased the pulley wrench and 36mm off of ebay for $46.00 incl shipping I had it in 2 days. I used autohaus for the pump. Gave them the number off the old pump still sent the wrong one. I couldn't wait so I capped off the opening for the oil cooler. Total job was less than 2 hrs..good luck