That machine is a dandy. There are no modifications needed to put on a hand crank, even an after market one. Just remove bolt from motor boss and place crank on. The originality of it is kept and you have use as hand cranked. I've rewired a 128-23 exactly like that with cloth cord from a sundial. Four screws loosened, new wire attracted, screws tightened down voila! The phenolic connectors look exceptional, which is rare. They come apart by unscrewing the top cap. You'll see the obvious screws to loosen inside. The other screws you have to loosen are those on the plug usually covered by the card board (cereal box works well).