Dating bedrock planes
For such a seemingly minor difference, the Bed Rock planes were offered at a premium over the Bailey's, and it was a design that never seemed to be very static nor nearly as popular as Stanley's wildly successful Bailey line.
Since the primary difference between the two models is in their frog designs, most of what follows is paid to that minutiae.
I can do everything I need with these extended length planes.
That said, I have longer planes all the way up to the #8‘s. Recently I found a Woden #6 plane on e Bay and would have bid a hundred plus for it had I needed to.
I also have to say that even though better quality planes are more rigid in the sole, I haven’t found them to be consistently true because of changes in the steel caused by different elements that markedly affect them.
These differences can be sole-hollow, sole-round and sole-twisted.
There are other considerations, perhaps the Bailey patterns worked just fine, but we will never really know.
I have owned three Bed Rock planes and never really reached for them because it wasn’t the shaving I was making but a piece of furniture or joinery. The longer planes do have a place at the bench and I would not be without the #6, 7 and 8 planes I own, but I never really use the #7 and 8 planes for flattening or straightening because they are rarely truly straight.
All the other makers for some reason copied the Bed Rock bench planes developed originally by Stanley in the USA in the late 1800’s and some of their other planes besides.
In other words, the frog does not mate with the bottom casting over the entire area of the frog's bottom.
So someone at Stanley, Justus Traut (the dude who gave us the #45, et al), sniffed out a marketing opportunity here.
Though most if not all modern makers have adopted the Bed Rock planes as standard production copies, the were actually rejected by craftsmen at their inception in the late 1800’s.
Perhaps it was over engineering and perhaps it was added weight.
If you don't wanna be stuck in the quagmire of frog design, best find something else upon which to ponder, like modern day uses of the amazing fiberboard planes, the #193AThe Bailey frog underwent several modifications in an attempt to make it seat better, and cheaper (each and every frog, and its receiving part of the bottom casting, had to be machined for a proper fit).