Perhaps it wasn't until Angier's later books that he began to directly credit Bo and the Randall shop?
I think that's probably the case. I finally gained access to a scanner so I could post these pages from "On Your Own in the Wilderness" (1964 edition). This book was co-written by the great Townsend Whelen, and it seems to be his 'voice' that's speaking on these pages. In the photo the knife on the right looks like an early Randall.
Edit: There's no specific mention of a Randall, but I think what Whelen says about knives in general is interesting.
Sorry for the poor quality scans.