I’m not even close to buying a sole stitcher, but I’ve been reading about them, and I’m very confused about all the different types.
The Landis 12 seems to have half a dozen different variants, for example. O, F, L, K, etc…
I think the difference is in the version mostly by age. In other words a K is older than an L. I have a K and an L and some of the parts are interchangeble and the both seem to have the same capability. I think technically they are different by minor version changes but between models (Like K and L) there’s not much difference whereas between F and K or F and L there are huge differences as the stitcher progressed and were made better by design.
I took a couple pics from the 2 manuals I have for the K & L machines I have here. Note the book for the L has instructions noted as “For Models K and L.” We use them interchangeably having acquired the K as a backup machine some years ago.
More research show our L model left the factory in 1956:
The Landis Model 12-L with serial number 56#### left the factory in 1956.
Historical records and trade knowledge shared among cobblers and cordwainers indicate that for the vintage Landis #12 series stitchers, the first two digits of the serial number denote the year the machine was manufactured. [1]
56 = Manufactured in 1956
#### = The sequential production number of the unit
This places your machine precisely in the early prime production era for the 12-L “Aristocrat” model.