Take a look at the FSR .10's case. It had the same Schneurle bulges cast in just like the .25, .40, .45, .60, .61 and .90 did. Now, remove the sleeve and look inside. It's a smooth cylinder. No boost ports machined into the case. The ports in the sleeve extend down into the case to receive the charge.

My guess is that OS wanted this engine to have the same outward appearance as the rest of the FSR line, so they cast a case with the fake bulges. There are three: one in front, one on the side and one on the back, just like the other FSR's, except these are all purely for looks.

David