Don't beat yourself up, the change happened long before most of us were born & it's probably only common knowledge amongst those who've read Patrick Leach's "Blood & Gore" from cover to cover & remember every word, or had personal experience. I discovered this little bit of Stanley idiosyncrasy quite a while back, but only because I got a new blade for my old type 11 & found it was too wide. What the??!! I then did my research & became a little wiser.
In my case, the problem wasn't too difficult to solve. The mouth of my old (type 11) plane is wider than 2 1/4" & I didn't have to grind that much off the sides of the new 2 3/8" blade to get it to fit comfortably, it was barely a mm each side as I recall. However, unless you are a masochist, you
will need some 'lectric assistance, modern blades are hardened for the entire length, not just the business end, so removing even that amount would be a rather long & tedious job by manual methods alone!
The alternatives are to search for an old 'genuine' blade (they do crop up occasionally), but that may take some time. Lee Valley used to sell 2 1/4" blades, but they seem to have stopped doing so, at least I can't find one on a quick search. An email to their customer service would soon put you straight on that score. Or you could ask Mr, Hock to do you a custom blade - it was $70 for a custom job a while back, plus postage, so not cheap, but he
does make very nice blades.
Some other potentially helpful information: most modern blades are thicker than the originals, some a good deal so. This can cause you two further problems, one being that the cap-iron screw may be too short to fit though the blade & engage enough thread to hold securely. In my experience it's rare that the screw won't hold well enough, it's more an inconvenience because instead of being able to loosen the screw enough to slide the cap-iron off, the screw comes right out if I'm not paying attention & I end up searching for it amongst the shavings on the floor!
The other problem with thicker blades is that the cam of the adjuster yoke may barely reach the slot in the cap-iron. This means that only the very tip touches the edges of the slot, causing a) a very restricted amount of blade travel & b) lots more backlash. Again, manufacturing tolerances means there's a wide range & in the majority of cases you won't have a serious problem, you'll probably just notice a small increase in backlash. I've not struck a situation myself where the cam failed to engage enough to get sufficient blade travel to be usable, but I have heard of it. So it's usually just a matter of learning to live with slightly sloppier blade adjustment. This bugs some people no end, though I have yet to figure out why - it's different on every Bailey type plane I own, ranging from little more than a 1/4 turn on the 'best' one to a full 2 1/2 turns on one very worn old workhorse, but I'm so used to it I hardly notice....
Cheers,
Ian
