Follow this link for the relevant pages from a Mathieson catalogue of the late 1880s for part of the answer. At their peak, Mathieson may have been the biggest toolmakers in the world - when so many of the world's ships were built and fitted out by the skilled craftsmen of Clydeside.
You'll see that they listed infill shoulder planes in widths of 1". 1 1/8". 1 1/4" and 1 1/2", but also 'rabate' planes in narrower widths.