@roffman. That would make the outer shim 2.9mm using the Puch service manual method. 3.7 - .6 - .2 = 2.9.
It was not clear to me whether the starter plate and retaining ring should be in when doing the service manual measurements. With it in there is a gap. Without the plate the gear sits right on the circlip and the .5-.6 would be the lower shim.