Wally, it is a
15K91 as it was made in Kilbowie. It is
not a 15-91, which would have been made in Elizabethport,
nor is it a 15K-91 as I have seen it referred to, as there is only one digit or character between the class and variety of the machine. As explained at
https://www.singersewinginfo.co.uk/class_numbers .
Janey - Neat people never make the exciting discoveries I do.
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