Boye sold five different needles that are considered "20x1", #4,#12, #14, #21, & #24.
#4-New Home
#12-White
#14-National
#21-Eldredge Rotary
#24-New Royal OS, Royal St John
I don't think the vibrating shuttle machines would be very fussy. Tip length might come into play with the Rotaries.
Here are the exact dimensions if needed:
https://docs.google.com/viewer?a=v&p...NDUxYzA2ODg5Nw
Jon