None of my keys will completely slide into the lock on the passenger door of my 300SD. The driver's door and trunk locks work fine. On the passenger side the key will slide about 3/4 in, but no further. This makes it quite difficult to be a gentleman and open the door for my passengers. I would prefer not to replace the lock cylinder, and by that I mean if that is what I have to do it will remain unfixed. Any suggestions?

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Ben

The MBs:
1976 300D (W115) - 330K and still going (sort of)
1991 300D 2.5 Turbo - Sold at 221K
1983 280SEL - Sold at 206K
1981 300SD - Sold at 232K