The TS has a multi-plate wet clutch, tensioned with 6 springs, each in their own spring cup and locked with individual pins (5mm long, 1mm across). Others here will confirm my feeling that taking it apart to get at the locknut is the single most unpleasant job for repair work on a TS. You'll need a special pusher tool, and a sheet or a friend to help catch the pins when the springs try to ping off over your shoulder at high speed. Lean the bike against a sturdy wall, too, because those springs are HEAVY.
The crank oil seals are under the clutch bell on the left side and under the commutator on the right. Removing the commutator is easy, though - just lock the piston, undo the breaker cam and screw in a 100mm long M10 bolt until the whole thing just pops off. Watch out for the woodruff key, but likely it will have seized into the shaft long ago.
For pictures/details/anything else, you could check
http://www.miraculis.de/aw/mz/text/ts1215r/ts1215r.html.
Use google translate if you don't read German. It's the best repair manual for the TS - the Haynes "Big Book of Lies" manual is loosely based on it, but the original is far, far superior. I've got an English PDF version somewhere, but this board won't let me upload it.
Good luck with it - once you get her running, TS can be quite fun.
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