...Nearly All Good Bookkeepers

The Wifey and I just bought a whole bunch of ephemera and paper from a local dealer's estate, and we've gone through most of it, rather quickly, and now we're looking inside everything. One small booklet, "Common Trees and Shrubs of North Dakota", came with this pseudo-bookplate, rubber-stamped on the cover:

This book belongs to James L. Helm, and please return it. You may think this is a strange request to make, but although many of my friends are poor arithmeticians, they are nearly all good bookkeepers.

Ah, the droll wit that insults friends' math skills and then accuses them of thievery! History attributes the quote to Sir Walter Scott, the Scottish novelist who penned Rob Roy and Ivanhoe. The quote has been in use for quite some time — Google Books' ambitious digitizing project includes numerous bookplates that quote Scott's "strange request."