From MAD Magazine #21 1955
An accessory worth having!
A clever,spring-piston powered air pistol first sold in the late 1940s. Initially the Marksman(MP) was a single-shot gun.By 1958 it had a magazine facility that housed BBs.(MPR)
The Marksman factory was located at three different addresses. Adverts in boy's papers and hobby magazines,made the Marksman a very famous air gun. Looking good but very under-powered,this pistol brought joy to many a boy!                         An extract from WHB Smith's GAS,AIR and SPRING Guns of the WORLD says it all!
1949 Marksman Air Pistol flyer-courtesy Dean Fletcher
Los Angeles 25 California
Torrance,Ca.
1949 October issue Popular Science. The Harris Marksman
1950,Kleins advert in Popular Mechanics
1952 Popular Mechanics Advert

1952 Pistol-courtesy Prof.John Griffiths 

1963 Marksman Adverts
1968 Marksman Flyer