For the Worldpac cylinder there are several on-line vendors. Here is one:
Canada Parts Online - 1985 Mercedes Benz 300D Base 5 Cyl 3.0L Ignition Lock Cylinder1985 Mercedes Benz 300D 5 Cyl 3.0L

and German Parts in Toronto (usually source from Germany)

GermanParts.ca

But I ordered the JL cylinder from this one who, although in USA , offer fast duty free shipping into Canada:

Mercedes Benz parts Canada and Mercedes Benz OEM auto parts online Canada

In case those links don't show up, I have PM'd them to you.

PS: I don't know why ordered a new cylinder. The one I ground down is working just fine. In fact I can start the car with any key or even a scewdriver, but everything still looks standard!

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5