Thanks for all the replies, but perhaps I was not clear with the question.
The long and the short of it is that now the heater core is no longer a problem. This is on my '88 300E.
The problem is coolant dripping from along the pan rail on the passenger side directly under the a/c compressor and a few bolts back.
I cannot see the weep hole on the pump or anything else below. This area cannot be seen because the a/c compressor and other accessories obstruct it.
Has anyone ever experienced this before? I thought maybe someone, especially the pro techs may have an experience base surrounding this. I hate to buy a pump that I don't need, so I suppose I'll start tearing things out of the way and look for the leak before buying a pump.