Following an 'altercation' with my garage door, my driver's side wing mirror is 'wobbly'. All the functions work OK and the glass is intact, but the assembly is loose and vibrates on rough surfaces. The problem appears to be internal retaining screws on the framework; the lugs have broken. I don't wish to pay the main agent £500+ to replace the assembly; so I have a couple of questions.
1. What is the correct part number for the Driver's side wing mirror assembly? Is C2Z19368 correct?
2. Is it possible to buy individual assembly parts, or do I have to buy the complete assembly? Is it wise to buy the complete assembly? The colour matched cover is intact, so colour isn't an issue.

I will be most grateful for any advice/tips.
John