I ran into this issue with some repro turn signals I got from PartsNMore.com.
The stock front signals had two wires, one being the hot for the turn signal and the other the hot for the running light. Grounding was accomplished through the metal casing, with the ground wire from the wiring harness attaching to the base of the turn signal stem inside the headlight bucket. The socket for this light has two contacts for the respective filaments, and the socket shell forms the ground.
Now, the rear signal, being mounted on a rubber isolator and containing only one filament, has one hot wire for the signal and a ground wire either attached to the metal housing, or the metal base the signal stem attaches to.
The light I bought said two-wire type, so I thought it would work with the running/signal setup, but it turns out it was for a single-filament bulb and the other wire was for the ground. (applicable to the rear signal lamp) So, it didn't work. I think you might run into the same issue. If you can swap the sockets too, they could work as you want them to.