From what I have read:
The Franklin brand of sewing machine was a model line offered by the Domestic Sewing Machine Company of Buffalo NY after winning a 1899 National Export Exposition award presented by the Franklin Institute of Philadelphia.
In 1911 Domestic sold both their 'Franklin' and 'Minnesota' labeled sewing machines through an agreement with Sears & Roebuck. The machines were nearly identical copies of the Singer model 27/127. The Franklin models remained mostly unchanged when White purchased Domestic in 1926 and continued sales of both the Franklin and Minnesota to Sears.
So there may not be a model number on a 1911 or later treadle Franklin machine because "The Franklin" was the model. White didn't change it and only replaced it with The Franklin Rotary in 1932 (which bombed in sales, and was renamed to become the first Kenmore labeled sewing machine in 1937).
Of course, what I've read may be sketchy in facts.
Last edited by Steelsewing; 07-25-2018 at 08:48 AM.