Depends on what you want to do to your TS. 'Cafe racer' implies modified and/or well looked after, so you might not have to do much except check the piston & rings, the timing and maybe the the dynamo and carb. Everyone here will tell you that the Haynes manuals are god-awful - the info in them is either half complete, or out-and-out lies. But if you're not planning on doing a full strip-down and rebuild, you'll find it adequate. The Haynes should cover the TS 150 and 250 versions - TS125 and TS150 are essentially identical except for the piston and final drive sprocket.
For a proper run-down, or if you want to get further than taking the side-panels off, here are the MZ manuals (owners and workshop) -
http://www.miraculis.de/aw/mz/mzli.htmlThey're in German, but Google translate will give you a fairly decent english version. I have a PDF of the English version somewhere if you're desperate.
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