Found this 1952 (301, not 301a) one at an estate sale with the bobbin case missing... I am going to call out all of the people that steal them out of the machines at sales; shame on you. Anyhow I got an original replacement and it it runs beautifully.
Although very grimy it is virtually scratch free and is cleaning up slowly. And since I am calling people out I will make my complaint regarding the crappy paint Singer used on these mocha machines WTF! you know what I'm talking about; it has poor surface quality, has to be cleaned very carefully, and more than likely will always have some blotches in the end. One of the failings of a large engineering company is that a penny saved on a million units makes a healthy bonus for some hack executive.
For my automotive reference I'm bringing in the late 60s BMW (had one of these.)