That looks like the part.  There is a plastic bit with a flat rubber ring around it, but it doesn't seem to seal anything so I'm thinking it's the inlet pipe part.  The high idle is persistent from starting.  I can idle it down with the idle screw, but it immediately idles back up to supersonic.  The screw placement doesn't seem to be particularly related to the idle, as no matter what position it's in (1 1/2, 2, 5 whatever) it continues to go back to the screaming idle.  If it was just out of adjustment, wouldn't it stay at whatever it was rather than changing back to the high?  
 
The part pictured above does not seem to have a gasket on the mating surface, so do the rubber things seal the air out between the cylinder and the carb?
 
Haven't looked at it today as planned as situations arose.  Hopefully tomorrow.  

Dating the saw is easy enough. What is the serial number?

.