One of the easiest machines to install the bobbin case I have used and again, the sound at any speed is smooth as silk.
FYI, I figured out how to fix the yellowed numbers on the 0 - 5 front dial. The dial comes apart fairly easily, take out the numbered disk and scan it at a hi resolution and Photo Shop the UV yellowing out of the scan. After you print it take some clear hard packing tape and cover both sides, then cut it out with an X-ACTO. I found it so annoying to have the whole machine cleaned up except for the yellowed numbers.
Recently sewed an organza bag with a tie at the end, the free arm made it a snap.
1957 Mercedes-Benz 300SL