Check the various Star Decal sheets of M55 quad gun trucks as they offer a few; some have ground mounts as well. They come with templates for the different shields on them.
I used a Star Decals sheet and shield templates recently on my “Easy Rider” gun truck.
M54A2 Quad .50 Guntruck “Easy Rider” - Armor/AFV / Cold War - KitMaker Network
