I had an engine like the third one also,came from a craftsman weedie.muffler is held on by a spring.still have the reed valve and carb but tossed the rest.i get my bearings and seals from (Boca Bearing Company).when you order a lot of them are shaft size,outside diameter,then thickness.for instance an echo 61 twin cyl crank seal would be(15x35x6) in mm.doesnt matter who the manufacturer is because a lot of chainsaws use the same seal no matter what the brand is.The last seal i ordered i called them up and had it in 2 days for a low shipping cost.they also have some ceramic bearings for some applications.