jgalt,
Are you referring to a '54 car radio (there were no pushbuttons on the 54 truck radio)? Does the radio mount in the dash of your truck?
Most likely the two wires are for the radio power and radio light bulb (as you stated). Both are 6v and you should be easily able to test which serves what purpose (ground the case and feed 6v to each wire (one at a time). If you have a good light bulb, you will soon figure out the leads.
The truck radio had two additional leads that were soldered to the speaker (mounted on a plate on top of the radio). The 53 manual-tune auto radio that I have seen has a phono-plug outlet for speaker connection (this plug may not be original). How do your speaker wires connect to the radio? Are you able to post a picture?
Good luck,
Tim
