Ah, the old CS60S. Echo's longest production run model, by far. Really tough saws, those!
My brother has one, that he picked up for ~$20 at a garage sale! Goes well, too. My old man still has a CS302, too. All Mobilco Echo's.
The CS60S was unique for an Echo of that era, in that they were the only model that used the crankcase pulsations to power the auto chain oiler. It was a common system on other brands of the day, but AFAIK that was the only Echo brought to Oz that used it.
The others all used mechanical drive piston [cam ground on crankshaft actuated] oilers; though the 601 setup was a bit weird, in that it was driven by a cam on the clutch drum centre. Again, unique to that model. When/if the clutch drum wears out, that will spell End Of Life for my oldie.
