you are welcome. you know
A) I have to wonder if the newer Mixture Control Valve from the OS 60L Carb will work for you, I am sure it will fit, you can find out by checking the O-rings part number or OD/ID sizes..
B) most likely the OS 65AX Carb will fit your engine, or, if your Carb has the same ID/OD may be you can use a Heli Carb, there are a lot of used ones around, even new ones, ask me how I know
,,, don't buy the OS 61FX Cab !
C) you should remove the Carb and muffler, and back plate and G-plug, or for that mater remove the head and soak it all in hot Antifreeze (not on high) for 6 hours and then clean off the Antifreeze well with WD40, it will be clean as new, if it comes out dark grey don't worry the WD will bring back it's color if you rub it in
Jim