I picked up this machine (Union Special #52900 BN) last year and I haven’t figured out how to use it. The previous owner (97 years old) said it “worked like a charm” when he stopped using it. I cleaned and oiled it per instructions. The cutters aren’t aligned correctly and having issues threading it. When I run it without fabric or thread it hums along. I have the manuals and extra parts but they haven’t been useful with my skill set. I live in northern Minnesota. Any suggestions?