The 10.5cm leFH (sf) auf Geschutzwagen H39(f) was a battlefield rarity. It never got a "nickname" that I'm aware of. What might think the troops operating it (21PD) call it? "Geschutzwagen"? "G-W (or GAY-VAY)"?
I have the Heimdal book on the 21PD and don't recall any discussion about this. Can anyone chime in with opinions?