Today’s Poster is a classic Shell oil item.
The Smithsonian’s catalogue reads: “‘FOR HIGH PERFORMANCE LUBRICATION BY SHELL.’ Framed multi-color print advertising for Shell lubricant. Illustrated with three Bristol Bombays flying over the English countryside.” Artist Karl Felkel (Austrian, 1896–1973).
James Kightly, Vintage Aero Writer.
Source, National Air and Space Museum here.