My personal observations after building four runners out of seven parts saws. First thing to watch out for is the very early glued on fuel tank and oil tank covers. View attachment 205985 Glued on fuel tank on the left. Notice the lack of cap screw bosses next to the bucking spike rib like the one on the right. They will leak sooner or later, all it takes is yanking on a pinched bar. Next item of interest is a change from three screws to five screws on the "magneto backplate". View attachment 205987 View attachment 206009 As one can see if a screw gets loose on the '3 screw' it can cause the backplate to wallow out the bore in the crankcase. A problem Homelite solved with two extra screws and, from what I have found, some thread locker. Some time or another Homelite increased the cylinder spigot diameter from 1 15/16" diameter to 2" diameter. Possibly to accomodate the increase in bore for the 57cc version. View attachment 205989 You can use the small spigot cylinder in the larger pilot bore crankcase. Not the best practice, but it works. Continued in next panel.