This level of art painting is found all over the place. On toys, Easter Eggs, flower pots, and just something people do to pass the time. To find it on a shooting target isn't too surprising.
Air rifles weren't cheep in the day, nor was the ammo. Not surprising such elaborate targets were made for the market either. No TV or Playstations then. Suspect it was their equivalent of a "shoot'em up" video game.

Really fun item from the past. Shame to shoot it up now, but making a reproduction and shooting that would be fun.