Slightly off the OP, but some year's ago, I bought a Stanley carriage plane(?) at auction, which has the cut outs to the sides and a full width iron. I posted about it a couple of year's ago, largely moaning about the poor quality and the fact that, no way can I get the blade to sit square with the sole, and cut properly. Curiously, surface rust has a different crackle finish from usual.
I got very fed up with trying to sort it out, and left it on one side until Steve's problem got me looking at it again. I suspect that the frog u/s is out of parallel with the blade bed, but rather than to resort to filing I compared the frog with other planes. The width seems to be the size of a number 3, but comparing it with a spare no.3 frog, which seem to be much more difficult to find, the bedding screws hole pattern and the position of those holes relative to the front edge of the frog are different.
This is probably getting a bit esoteric, but does anyone have any ideas/information?
Mike