Harm, it looks like you got an underwhelming response so I'll chip in...
The 60 SR (known affectionately as the FSR) is OS's first schneurle ported front induction .60 sport engine. Its predecessor was the crossflow scavenged FGR .60. It was released to the public in the mid seventies and represented a quantum leap in performance, consistency and user friendliness. Even by today's standards, the FSR .60 is an excellent sport engine. Its historical significance to the RC world justifies its status as a real "keeper".
The early models came out with an OS 7B carburettor and used a custom OS160 rear bearing, still available at Tower right here...
http://www3.towerhobbies.com/cgi-bin...?&I=LXCD19&P=0
Later FSRs (renamed .61 rather than .60) used the commonly available 6903 rear bearing and were supplied with the OS 7D carbs..
The FSR line uses the OS 744 muffler (not to be confused with the 744B), which as you will know uses bolts that thread into the crankcase and, in the event of a crash, will damage the crankcase around the thread.
The bad news is, because the engine is more than 30 years old now, you can't readily buy the crankcase and other major components any more, unless you come across them in auction houses and other outlets. With your engine, you may have to mount the muffler with a strap, like the really early RC engines used.
Let us know how it goes once you get it going.