I've tried dougrussel and every other online broker/dealer I can find, it's not available in aftermarket. I've even tried Camp, whom I beleve was the aftermarket manufacturer, looking for technical drawings so I could machine on myself, but they didn't even respond to my inquiries.
I did however, order and recieve a wrong part, that I might be able to jury rig with an adapter plate...but I'd certainly rather find a salvage yard that I could pick-n-pull the part...
Not knowing where you are located makes it rather hard to recommend a salvage yard where you can pick-n-pull the part.
the best salvage yard is ebay.
dougrussel is a Merc dealer and sells the factory part. If they are out, then try a local Merc dealer. The part was available from the factory 2 years ago, so there may still be some sitting at dealerships.