My 1986 300E with a 5-speed manual exhibits shifter-slop.

The 5-speed is so rare, that it is not surprising that I have been unable to locate anything about this problem on the 'net, or this board.

It would appear that the mechanism in which the shifter lever pivots has a fair amount of excess play.
I recently removed the shifter boot, and lubricated the entire mechanism with lithium grease.
This improved the smoothness of the shifter operation dramatically, but it would appear that the various plastic bits were already very warn, or coming loose, so the excess play remains. Much of the problem appears to center around the reverse-lockout feature and related bits.

Years ago, long before I inherited this car from my aunt, this was one of the best shifting cars I had ever driven. 180K miles later, the shifting action is far from sweet.

Before I tear into it, has anyone undertaken this project before?
Can adjustments be made to solve this problem?
If not, what parts do I need?

I would rather not disable my daily-driver while waiting for what will certainly be 'special order' parts.
Thanks so much for any insight.

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1986 300E 5-Speed 240k mi.