That looks like a PL-5 with SL type fuel and oil caps. The other must be a PL-4.
SL/PL-4 is a 46mm bore and 59cc. PL-5 and SL-11 is the 48.5mm bore and 65cc.
The above could be either as the recoils interchange. Only way to tell is with the popsicle and dial calipers method.
I used a piece of wood to get the rough measurement. Didn't have any popsicle sticks in the garage. When I get home next week I will pop the saw apart and check it with a caliper.
What is the SL- number that matches the PL-4? Just for clarification, so I know what parts saws I have up there.