Unfortunately where the 251/10 D is concerned, this smacks a bit of opportunism to me - the dies are all existing, it's just a shake up of existing parts, & as Catch 22 & Jim say, it's unlikely if not incorrect. The height of the full shield was a problem that was quite quickly addressed, photos of Ausf C vehicles commonly show the cut down shield, or even lack of one altogether. However, it is likely that some sort of close support weapon was deemed necessary in the panzergrenadier platoon, since there was widspread adaption of the 2.8cm Panzerbusche to this role evidenced in Normandy, so an Ausf D 251/10 is possible, but definitely without the shield. The 251/10 was usually issued to the platoon HQ halftrack BTW.
I'll be after the Sdkfz 250 though. The box art looks like it came straight from a photo in the After the Battle "Ruckmarsch" book.
"Lord Raglan wishes the cavalry to advance rapidly to the front, follow the enemy, and try to prevent the enemy carrying away the guns. Troops of Horse Artillery may accompany. French cavalry is on your left. Immediate. Airey."