Chuck:
Your truck has ‘41 parking light units- completely different from the ‘42-‘46 style that replaced yours. Apparently, someone changed yours at some point- for reasons unknown.
The ‘41 units, like yours, are an involved cast assembly made of of several parts. The bulb fixture is in the parking light assembly.
The ‘42-‘46 units are a simple stamped steel cover with a shorter lens. It covers a bulb holder that is part of the headlight can.
Unless you’re hung up on originality, the easiest thing would be to retain what you have. I hope this helps.
Gene
