It may or may not have been a Holden dealer who replaced it. Many dealers and parts shops offered genuine Holden parts without ever selling cars or having a mechanical shop.
I remember buying a lots of Holden spares from South Coast Agencies in Wollongong. Also places like Bennett & Barkell, Bennett & Woods etc. These wholesalers would stock and supply local mechanics genuine NASCO/Holden spare parts. Would have been nice to have the paper work for it. But as you say, you'll drive it with a smile on your face!