As I said, wish you the best with it. TW Chambers do offer new/second hand Hawk foresight parts if you look at their site. Not sure which model you have, Mk 1, 2 or 3? They seem to have parts for the last 2 models.
Seriously, watch the trigger assembly/safety catch - mine was downright dangerous. My various grand sprogs shoot with most of my small collection, under strict supervision.
I hope to be doing up a BSA Meteor for their use soon - they've outgrown the Webley Junior rifle, & I'd rather they keep their mitts off my classic 'Sporters & Mk 3's...the HW's are a bit heavy for them.

All the best

Bru