I have several issues of Argosy magazine from 1930, all of which feature John R. Neill ill- ustrations. Argosy was a ten-cent weekly pulp magazine which published a range of action stories - some of these were later published in book form, but without Neill's drawings. Neill illustrated stories in Argosy for several years, with drawings that range from the mundane to the supernatural.
A regular feature of the magazine at this time was an article called The Men Who Make the Argosy. In the issue for November 8th, 1930, Neill is featured in a short autobiographical sketch. This is an interesting article with various bits of information - one of my favorite tidbits is the mention of buying shares in a Mexican silver mine after dreaming of doing so - and then watching the price for silver drop! When I visited Neill's granddaughter a couple years ago, I saw several southwestern drawings that may well have been from this period.