Hello, I am looking for more info on my singer 241-12 from what I have learned it was made in 1942. I use it mostly for denim. When I bought it 4 years ago it had been sitting in a garage for at least 7 years not ran. It did start and I took it home. I replaced all the things. New belt, new gasket, new oil. Adjusted the stitch length etc. I have read the manual back and forth. What I don’t know much about is the actual motor. I need to know how I service it or what I need to do to keep it running well. It looks like there are some oil plugs in it? The motor runs great and sounds great but can anyone steer me to more information on servicing? Thank you