Yes- the # on the NAPA box is 1010. But like I said before, this filter adds 1/4" of height to the whole assembly, including disk, so I could not push the housing up with enough force against the spring to get the bolt threads to engage. I had also noticed that the metal "rise" in the centre of the 1010 filter's top plate is of the same diameter as the centre "hub" of the disk itself, yet it would not fill in the vertical space normally occupied by the disk. I don't need a new disk- I simply left it out of the assembly so that the filter would bolt up. When I get the right filter from MB, I'll put the disk back in.

When I gave the MB dealer the VIN number of my car, he gave me this part# for the filter he will be ordering for me- 0001800209, list price $8.17 Canadian (which is pretty cheap).

It would appear to me that the function of this disk is to give enough space for the oil to bypass when the filter becomes plugged. With the disk not there, there should be no danger as long as the filter is not plugged, except that the filter is probably not seated tightly against the spring and so some oil could drift around it instead of through it- kind of a "partial bypass" situation. Anyhow, I hope to have it all back to normal when the new filter comes in next week.

Thanks All!