Vactron Radio Tubes appear to be branded by
Rhodes - Burford's Exchange Company, 4th & Broadway, Paducah, KY, USA
Last seen: 20-Oct-1927
I find only one ad run in two newspapers, Richmond, Indiana; and Louisville, Kentucky.
The Vactron UX201-A appears a standard tube with envelope label. This one tube from an old eBay auction shows the design.