If you search for WC-54 Signal Corps vehicles, there are a lot of modern day restorations, yet few photos exist from the war.
The two radio vehicles commonly used by were the Dodge WC-53 Carryall, and the K-51, based on the Chevy 1.5 ton Van. The latter pulled a K-52 Ben Hur trailer with a generator.
Both vehicles have a superficial resemblance to the WC-54. While some WC-54s were used by the Signal Corps, I've often wondered if some of the restorers have been a little bit confused by the WC-53 or K-51.
Even this website calls a WC-53 Signal Truck a WC-54 (scroll down to "Signal Truck hit by German fire"):
Wikipedia has a better image of the WC-53:
And a picture of the K-51 with K-52 generator trailer can be found here: