WELCOME to this forum, I hope you'll have a pleasant stay with us !
The 46th Armored Medical Battalion was the organic medical unit of the 4th Armored Division. The Division although arriving rather late in the UK (11 Jan 44) did however participate in quite a number of operations on the European Continent, thereby receiving the following Campaign Awards: Normandy, Northern France, Rhineland, Ardennes-Alsace, and Central Europe.
As per AR only Ambulances were to receive Geneva Convention symbols, and it was the CO's choice to issue any instructions to adorn 'medical' vehicles in his command with additional flags or painted symbols. I'm not particularly fond of adding more symbols, except maybe for a flag, which was generally accepted and even sometimes recommended ... (Stock No. 5-F-2150)
Good luck with your project and I hope you'll share some photos of your vehicle with us later.