Jeff,
Looks like I have a similar problem with my 95 300d and thanks to your posts I can breath a bit easier knowing that I have a relativily simple explanation for what has developed into a siginificant leak at the top of my IP. I performed a search and found the following link which might help you.
http://www.peachparts.com/shopforum/showthread.php?t=128675
93 300D 2.5L Injection Pump seals - ShopForum
But I can see that removal of spline nuts is a bit of a challenge for my unit as there are no "large nuts" at the base of the spline....must be a newer design that probably requires a special tool to loosen the spline......
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Guess I will keep on searching or get some guidance here.
Good luck
Brock