I've been looking for a source of B&S 1 taper arbors or other accessories but not seeing any located at tool suppliers. The B&S tapers are a somewhat old standard, and aren't as commonly available, particularly the small ones, as many of the other tapers are.
If anyone knows of sources or has any pieces that aren't being used/needed, I'd appreciate hearing about them.
The #1 is under 1/4" at the large end, and about 1" long.Deckel and others used a GA taper shank, which is likely also a B&S #1 taper (not confirmed).
Gorton, Green, Lars have apparently utilized this taper for small tooling.