There was another one in Battlefield 1 - an experimental machine gun with two magazines, but only one could be engaged at a time. You would pull one out slightly and push the other one in. The idea was to be able to switch between two different types of ammo for increased versatility (e. g. regular ammo against infantry and incendiary for anti-air). As with most weapons featured in Battlefield 1, I think this was a prototype that never saw any real action.

:る

Looking at the “damage” - it seems whoever removed them used a hard scraper and some sort of aggressive solvent. This is not damage from the googly eyes, but from the hands of the remover, who probably had too much caffeine and enthusiasm that day.