Say what you will about Bob Crane, but don’t forget to mention he was seen using an Eberhard Faber Blackwing.
Since the Blackwing first appeared in 1934, I suppose it’s technically possible one could have found its way to a prisoner-of-war camp in World War II Germany (the Eberhard Faber factory in Germany, however, did not manufacture the Blackwing 602). But I’m not so certain that the creators of Hogan’s Heroes were all that concerned with historical accuracy.
The mid- to late-1960s, when this series was televised, was a significant era for the 602. The first and only national advertising campaign for the Blackwing, designed and implemented in 1965 by Julia Faber (the widow of Eberhard Faber III), appeared in several magazines including The New Yorker.
Thanks to reader Dan for the tip!