I come bearing gifts.
Here's what I've learned... Falcon uses the following keyways for their SFICs (their conventional cylinders have another system, just a standard three-level tree):
But see that text? It's true! BEST, Falcon, and Arrow -- for the most part -- use the same keyways.
Okay, I'm stretching here, because I can't actually verify that vis-a-vis Arrow. But I know it's true for BEST because it matches what the Ilco catalog shows, both the keyways and the names. The only thing Ilco has that's different is the aforementioned FM keyway...
... which I assume is Ilco's own creation. And I dunno what it's for; you can see that while the IC keyways have quite a bit of paracentric variation, a good number of them DO share similarity, so it's quite possible that the FM could fit at least a few of them. Maybe someone with better eyes than me could superimpose the keyways and see what lines up.
Falcon uses the "A" keyway standard on its ICs, by the way. So what I'd really like to know is whether BEST has a similar default, or at least some preponderance; I have a hard time believing that they just have a dozen+ keyways in a hat and install random ones into each cylinder. Not sure about Arrow either, their literature sucks.
Making good headway, though. This is how you learn stuff, folks.
Another tip -- I was curious why the Ilco catalog didn't show variations for different pin numbers, then I remembered that BEST keys are tip-stopped. You just cut the blank as many times as you want! This may not mean much to the rest of you but if you're trying to reconcile bump keys and increasingly realizing that they basically end up as (keyway variations) * (pin variations), you'll understand that I'm very happy the "actual" number of BEST keyways isn't 18 times 2 or even 3.