Right: made in England notably wider at 2 7/8″ with sides 1/16″ thicker.
Here’s a gathering of possible info that considers type studies for English Stanley’s, started by Zeta in a woodwork forum Tools UK bought JA Chapman in Sheffield and started making planes in 1937.
I didn’t think Stanley started making plane there until much later. Now, interest is rising again, check the IG posts on them, proud woodworkers and their English Stanley’s.
They did move tool production there, but the plane production is still a mystery with conflicting information. No 4 1/2 smoothers English (type study draft below). (NB: adjusting nuts went from brass to steel to brass and back in this period.
Four categories seem sufficient to describe and roughly date a plane: Pre-lateral for any plane that has no side adjusting mechanism for the cutter, low knob, SW model or tall knob (SW stands for Stanley Works but is usually called Sweetheart) and late models for WW2 vintage and later.This information was originally on Jay Sutherland's website, but it went inactive sometime in 1999 or 2000. The screw may then be tightened, by a turn with thumb and finger; and the Cap iron will serve as a convenient handle, or rest, in whetting or sharpening the cutting edge of the Plane Iron." There you have it, in all its gory, why the circular hole was repositioned, after it being at the top of the blade for some 100 years. However, the patent drawing for the change shows what I believe is the real reason for the change - the circular disk, on the lower end of the lateral adjustment lever, loses its ability to engage the slot provided for it (in the cutter) when the iron is nearly used up.By relocating the circular hole toward the bottom of the cutter, the iron can be used right up to the slot, without sacrificing the advantage gained from the lateral adjustment lever.Start by reading Patrick Leach's comments on Stanley plane dating. If you thirst for heaps of data on plane dating, visit the Plane Type Study or the Plane Feature Timeline. This page leads you down a hypertext flowchart to determine your plane type.It includes links to Patrick Leach's original Plane Type Study and the Plane Feature Timeline.The 4 1/2 is 10″ long (1″ longer than the No4 and 3/8″ wider with a 2 1/4″ cutter) and its increased mass makes it hard to work but a very effective smoother. Blade tops changed to rounded at some time C1960s Y-levers went from cast to two-piece stamped and back to cast again at this time) Type 4. Left: type 11 1910-1918 (APR-19-10 patent date added to bed) with wrong cutter and shop-made wood. The flowchart starts by asking questions about the cast iron bed of your plane.I've chosen the bed as a starting point because it has many easily identifiable markings, and it probably wasn't replaced that often.These features are avoided where possible, along with features that appear in only some planes of a given type (i.e. Where possible, the flowchart uses parts that were probably replaced less often, such as frogs, depth adjustment screws and lateral adjustment levers.This approach doesn't guarantee that you'll date your plane correctly, as the flowchart can be thrown off by some hybrids.Unfortunately, many plane types share the same bed markings, so other features are also used in dating.Some plane parts were frequently replaced by their owners, or are easily separated from the plane, such as irons, cap irons, knobs and totes, and lever caps.I intend to eventually format the data into a more usable format, but for now I want to put it out for reference and feedback.