on the walbro site there is a list of carb's and you can find out what it was put on if you know the manufacturer and type of engine(ie chainsaw weedie etc) the HDC-65C is from a super 2 apparently i am trying to find out for sure what the displacement is. the thrust bearing is the main bearing one the piston arm, no? the roller bearings on the crankshaft came out of the metal casing they were held in so when i get it back together i will have to re-grease them. the main thrust bearing is a roller type and seems smooth. did you cut off the clutch side shaft?

here is the HDC-65

HDC-65-1