Perché io valgo
If that's explains the differences between a Model A & a Model B...
... I am happy.
There was 2 patents for these machines... one for the flathead in 1946, one for the roundhead in 1950.
That would mean all flatheads were (A).
That would mean all roundheads were (B).
(and this independently if they have a steamer or not,
since Ennio Delle Vedove patented the head Steamer)
This business letter is part of my private collection.