ORIGINAL: crankpin
Skip - This should be in the ballpark. OS 61 SF. The ringed version is more popular, you can usually pick a NIB for $175-$225 range, on auction somewhere, and maybe cheaper. The FSR should be good also, 3 piece case, I have not run any of the FSR.
The above is only my opinion, not saying it is right for everyone.
Crank
crankpin,
i recently purchased an os61 fsr which is my first os engine. i saw the pictures you posted and noticed that the crank vent hole has a screw closing it. the os i purchased had a vent tube on it. do i really need the vent tube? what does it do for the engine? i will greatly appreciate your input.