Cruise stalks the same for all Petrol omegas (BMW diesel one is different). Clutch switch is on the pedal, up near its pivot point (you'll have to remove that card trim)
AFAIK, not only is it the same for all petrol omegas, but the one from the Sintra is identical, and So are some of the Vectra ones .
I replaced my Omega one with a Vectra one i got off ebay cheap (£4) when looking for a fault on my cruise control , then realised all 3 were identical.... , checked this by removing the fitted ones from both my vehicles and comparing the three, visually AND with a meter to check electrical operation.
as it turned out, my fault was an incorrectly changed brake light switch, the garage (no longer used! ) changed it for one from a non Cruise model... which only has half the contacts.... (non cruise ones are blue with 2 sets of contacts, cruise ones are black with 4 sets)
this switch interlinks with the cruise control AND gearbox , as well as the brake lights.... so it might be oin your list of things to add???
Max