In his book, John Garden provides plans for several "stock" wooden planes. He discusses the irons and the stocks separately. In the plans he does not give specific iron dimensions for the planes described. Assuming that the jack plane described on page 221 is for the narrowest jack iron referred to, we are left with a 1.75" iron in a 2.125 width body. Not much meat in the cheeks, 3/16ths were 3/8" would be more typical. Similar dimensions for the Jointer shown would be 2.125" iron in 2.5" plane.
I'm perfectly familiar with wooden planes, though not New England fashions in the mater. Can anyone confirm correct iron dimensions for the bodies in question?