MODERATOR'S NOTE, 9-2-2017: This thread was cleaved off of the ACC Vacuum Pod Replacement HOW-TO thread, as the subject matter applies more to availability of the pods, as opposed to the pod replacement itself.
CONFIRMING that pods 124 800 26 75 (defroster pod) and 124 800 02 75 (center vent flap pod inside evap box) are NLA from Mercedes-Benz.
The pod 124 800 26 75 is still available as a Behr (OEM) unit from aftermarket retailers such as AutohauZ, but unknown for how much longer.
The 124 800 02 75 is not available on the aftermarket. However, with care, it can be rebuilt with a new rubber diaphragm as available from Performance Analysis Co. in Tennessee.
I **highly** recommend that you purchase a spare set of the 124 ACC pods to have as spares, if you are a long-term owner of these cars. You will need to utilize both MB and AHAZ+aftermarket sources.
MB has dropped prices on the pods they do carry. Via http://www.mboemparts.com (MB Naperville, free shipping with "500EPROMO" code), current prices are:
124 800 09 75 - $28.49 (lower footwell pod, rectangular)
124 800 30 75 - $36.63 (recirc/fresh air flap pod, right side, 1994-95 / facelift models only)
124 800 29 75 - $36.63 (recirc/fresh air flap pod, left side, 1994-95 / facelift models only)
124 800 03 75 - $24.79 (diverter flap pod)
From AHAZ, the Behr pod is 124 800 26 75 - $60.63 (defroster flap pod)
I hope this helps folks. Generally when MB dumps prices on parts, it's a precursor to immediate "NLA" status. As it was, the 124 800 30 75 pod had to come from Germany -- not a good sign if they don't have it in stock here in the USA, given the number of W124s still on the roads.