Has anyone ever made a claim that stanley planes were pioneers in iron planes? ....
..... I don't think the dovetailed infills came until later (the castings were first) - i am a maker of planes and by no means a historian, though ....
Stanley was far from first - there were numerous patents taken out for iron planes before Bailey patented what we now know as a Bailey plane, in 1867. (Well it was close, the production model differed from the patented model by having the depth-adjuster thumbwheel on a horizontal stud instead of a vertical stud).
Stewart Spiers did indeed kick off with a cast body for his infills, in 1840 according to himself. I have not been able to find out excatly when he started dovetailing them, but it seems he was doing so by the early '50s so still well ahead of Lenny & the team at Stanley Rule & Level.
Dovetailed mitre planes were around much earlier - some think as early as the late 1600s, but the earliest model that can be verified is from the first quarter of the 1700s according to my sources.
There are earlier all-metal planes, mainly small instrument-makers types but a couple of smoother-sized continental planes from the 1600s or earlier do exist.
I'm not aware of any Roman planes found with all-metal bodies, the earliest ones found with metal parts (apart from the blade) were shod with iron, riveted to wood "infill" (or ivory in the case of the Goodmanham plane!)
......Bailey's innovation was making them inexpensive and useful....
And Stanley's contribution was
marketing!
Cheers,
Ian