I am looking for a specific part - photo attached.

its the pulley off the air con compressor - somehow it’s sheared off and fell to the bottom of my engine bay. My local garage have repaired the belt that it damaged on the way down but their parts supplier can only find the full compressor unit which costs £800 before parts and labour!

if I can locate just this part, they can fit and fix my air con..

please could someone advise where I may be able to get one from?

trying to ignore the fact that a car of this age should not have such a part just break off - no idea how or why but just need to fix it!