Hi Tenor Man;

That is the same failure mode that I had, except that your friction plates are not as far gone as mine were, and I also had a broken huge circlip.

My K1 drum also looked just like that. I figured that there was no actual material gone, and I don't think that there should be a lot of differential rotation under pressure requiring a smooth surface. The wear is caused by the broken parts contacting when they shouldn't. I just left mine. It seems to work fine, although I suppose it could be a time bomb.

The small seal comes in the gasket/seal kit. The only ones that don't are the two large ones hidden inside the K1 and K2 drum assemblies (the ones that you have to drill out rivets to get at). They are a bit tricky, but the Corteco pamplet tells you how:
http://www.transtec.com/tech_insert/94642.pdf at page 7. Mine were maybe still sealing, but they were hard like bakelite. I replaced the rivets with bolts as directed, and used lots of loctite putting them back together.

The springs and the broken spring holder are cheap from the dealer. I got a seal and gasket kit, complete with friction plates, on e-Bay. It was great. Most of the friction plates were genuine Mercedes. There is a kit for the 722.4 transmission on e-Bay now, which seems to include the friction plates (the picture is small), for $240 (which seems highish).

Andrew