There were a few factory-made Wahl-Eversharp Combo pens. Here are some examples:

This one is a pretty late (Oxford era) Eversharp pen in a dusty velvet green color. It is more slender than the pens that follow

And here is a full size Green-Bronze pen with the screw in golf style pencil

And here is what they call in Japan the Gantza Megilla; The full set of interchangeable parts in the combo range.
Pretty cool, Huh?
Syd