If anybody has a carbon Chinook boom tailpiece in any condition at all just sitting around, I would happily pay for it in beer or even real money

Try Steve at Steves Shed / Sails n Windsurfing Center OConnor.

Have you broken yours?

Thanks Chad. No I already have a six-pack ready here for when somebody finds a tailpiece in the back of their shed, but if that doesn't work out I'll drink the beer myself and get in touch with Steve for sure