What decals do you actually require? White US stars are readily available in 1/56 and their use became increasingly infrequent anyway. White serial numbers, the old USA XYZW type are also available in 1/56. Yellow USMC markings are a bit less common but I suspect, being yellow they are easier to home print and IIRC a couple of the Rubicon kits contain them.
If Empress or someone else do dedicated decals, that’s a bonus but I suspect you can find what you need already. Painting names, slogans and artwork is down to you though.