Not sure as the shape may be subtly different between the two. Doubt they’d have different steel (fender, hood) pressings so you may need to simply change the grill between the lights. As to the plugs, both have H4 halogen globes, if I’m not mistaken, which defines the connector type used.
Alternatively you could look at caprice headlights as some came with HID options. You’d need to bring across the front and rear height sensors, self levelling module, headlight washer system and wiring but the HID lamps would be miles better (and almost fully compliant).
if you have a series 2 Omega then they wont fit flush if it's a series 1 headlight. 99% certain will be straight swap with the loom side. I have a set of HSV headlights (They the same headlight as SSV / CalaisV) at the moment on my desk I can try get some photos if need