Welcome. Beautiful cabinet.
I always like seeing sewing machines stay in the family. My sister has the treadle that she learned to sew on.
Interesting as the bobbin area appears to be a #8 rather than "9" as shown on the machine. I think the 8 is thinner than the number 9 and both are called "bagel bobbins."
From my understanding there is a group that focuses on the early domestic W&W machines at
https://groups.io/g/Wheeler_and_Wilson-Sewing-Machines
If I remember correctly they take a different needle.
Janey - Neat people never make the exciting discoveries I do.