Most of what I know about Danish cartoons comes from sources like this, but these don't appear to be related.
Gaston information from here.
Danish STENguns: The Drawings from "Gaston"
For the exhibition "The fighting Denmark" in the summer 1945, "Gaston" made some satiric drawings. Here are two of them.
[1] Here you see the "Production Manager" from Holger Danske make drawings, assemble, and show how to hide a STENgun.
[2] Here is another one showing how Holger Danske tested the STENguns in a park in Copenhagen.
Who is/was "Gaston"?
The direct successor to 'Frihedsrådet' is the Frihedsmuseet, but someone burned the museum down in 2013 so they're closed. Anyway, their database is still availaible, though they have nobody with the cover-name 'Gaston'. As this exhibition (and the drawings for it) were made after liberation, it is possible this guy actually used his real name, which means it might have been Gaston Jensen, a department leader of Holger Danske. All other Gastons seem to have been detached at various military roles, this is the only one with an administrative function.