This is now but a draft that you can see for me to write about the early Iron Planes. The information contained herein cannot be verified presently…….
This unique shaped metal plane [ the ‘Norfolk’] may have been commissioned by John Monks & Sons in Sheffield [at a foundry unknown] and the casting sold to MARPLES, as well as other manufacturers [Robert Marples]. It seems likely that the decorative Shamrock cap may also have come from Monks, so we can assume that they also supplied the caps for Robert Marples too, but with a different design?
There is a suspicion that JWS [John Wolstenholme & Sons] may have been involved in this mix as well, as planes have been found with JWS cutters installed.
Type 1 may have a straight across brace/boss whereas Type 2 may have a semi-circular cutout on the brace to accommodate the cap iron screw head.
[Insert catalogue page here showing both the William and Robert Marples cat. pages.]