Well, all I could find in a quick Google search was this:
That would mean that the decal No. 4 would belong to a Sturmgeschütz unit of the 116. PzDiv.
They fought in Normandy, BUT as far as I know they did not have a Sturmgeschützabteilung, so unit insignias may belong to other units such as Panzerjäger or Panzer units.
According to Wiki (as reliable as that is) the order of battle of the 116. PzDiv was:
Panzer-Regiment 16
Panzergrenadier-Regiment 60
Panzergrenadier-Regiment 156
Panzer-Aufklärungs-Abteilung 116
Panzer-Artillerie-Regiment 146
Heeres-Flak-Artillerie-Abteilung 281
Panzerjäger-Abteilung 228
Panzer-Pionier-Bataillon 675
Panzer-Nachrichten-Abteilung 228
Feldersatz-Bataillon 146
Panzer-Nachschubtruppen 66
When I get home (in a few hours) I will take a look at my trusty books on StuGs and their units. Maybe I can come up with more information then.