A probable "freebie" from a big name in radio, back when the amateur radio market was a significant part of their business and a huge source of goodwill:
The logbook that goes with this is a real period piece: the back of every page is a catalog page for the company's products! It's actually kind of handy: a 28-page logbook, 25-page catalog, plus seven pages of useful reference data (including the inside covers). Don't look for a scan soon: "Entire contents copyrighted 1938, No. 267644, by Bud Radio, Inc. No portion of the contents may be used without written permission." I wonder what the present-day successor would say if I asked?
The logbook was used by R.E. Morwood, a fellow in Springfield, Missouri from 7 July to 23 September, 1939. All CW, much of it on 20 meters, a little 40m (at ½ one of his 20m freqs., probably on the fundamental of that crystal) and even some on 10m at its 2nd harmonic. From the logged frequencies, he probably only had two crystals, both on 40m. The handwriting is that of a young man; the last mention I have found online with that callsign is from a 1941 issue of QST, listing him as the Missouri Section Communications Manager and giving his first name as "Robert." Someone with a different last name holds the callsign now. The same name (with a different call, also now held by someone else) shows up as part of the team that pioneered amateur "Moonbounce" communications in the 1960, bouncing signals off the Moon to establish two-way communications between ham stations in Massachusetts and California.