Hello Sourdough, I have scrapped a Miller Big 50 and from what I can say of that I believe that it is simpler than what is required when you are dealing with one of the Lincoln SA's. If my memory serves me correctly you will find that it's easier to remove the engine from the armature/barrel than the other way around. In other words leave the fuel tank and all of the associated wiring in place and remove the radiator, motor mounts, and then the bolts around the barrel that attach the engine. Then I believe there is a shielding band that should be removed to provide access to the bolts that attach the armature to the flywheel, there is a machined recess that handles part of the alignment of the armature to the flywheel. Don't quite remember how tight of a press it is once the bolts have been removed but I don't remember it as being excessive. Support the barrel near the joint as it has mounts on the barrel and the engine to support the entire assembly. Good luck and regards, Allan

1 have an old big 40, early 70's, with a bad motor. If you need any spare parts, or something doesn't go quite right.