@aamays no idea on if there wiring is there to support? What's the connector look like, you got a picture? Always best to test for voltage present and operates as expected prior to buying parts though. If you haven't done that I'd test that out.
I've also been told the sidestep harnesses on the 1958s don't have power present on them even though the plug is there, but I don't know for sure on that? I know Eric of Ed Martin Toyota said it was possible to add step lights but I'm not sure if they have to be configured by Toyota or not to function. The interior lights have settings, but if IIRC they are all either enabled or disabled you can't turn individual functions on and off. There are however multiple part numbers based upon trim levels for the body control module which controls the lighting of both so that may be the issue if you don't have any voltage when testing.