You probably have a better chance of seeing a pink unicorn flying through the air, than you do seeing a vectra b at a breakers yard.
I must have phoned about 10 a few weeks back , no joy i even said they have one , then you go and it's a vec c
breakers were even saying a few years ago that they don't get them in anymore.
Not sure if the astra g is a different story.
It's possible though that one of the saab models may have what you need