They won't work worth a damn! ... the small inner reflector bounces the bulb "hot spot" onto the big rear reflector to blend into & form the beam, which is then focused by the lens.
The reflector in back can be a different shape for fog vs driving vs spotlights, but then it's more in the lenses as to how the beam is formed, focused or dispersed (fogs tend to disperse).
Unless you're looking for OE correctness, you're better off buying another sets of lamps in the pattern you want - driving, fog or spot.
If you're just looking for better light out of yours, then you can refinish or re-polish the reflectors & clean the glass lenses & polish the latter with glass polish or rouge to remove the years/miles of road grit sandblasting that they've received (same with the headlights). Even though the old school ones are glass, they still get cloudy from the blasting.
Tom
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