I have the VB to VK GMH parts & picture books, I'll have a look.

As Terry noted, VK was the only first-gen Commodore with a factory fitted sunroof.

WM/VE was the next model with a true factory fitted sunroof, although the 2nd generation (some models of Caprice) and 3rd Generation (eg VZ CV8-Z), offered a standard sunroof on some models/trim combos, these were done "offline" once the car was complete, and not as part of the production process.

This particular VB is definitely an aftermarket roof. It's done well, but is not "factory" fitted.

There was a myriad of different sunroof makes & models in the era. Companies like Hollandia Vermeulen grew by acquisition, reducing the number of manufacturers, and therefore condensing models, throughout the 80s & 90s, to the point where there's only a few brands around these days. Common brands from the era like Golde, Skytop, Astro and many others have all been either swallowed up, or are no longer in business - muscled out by the big corporate players.

I would have to say I've seen more than a dozen different types in VB-VH Commodores that I've looked at over the last 20-25 years. About 50/50 metal vs glass, although I have seen a couple of roll-back cabrio style canvas ones as well. Some of the metal ones had a basic lever action to release them, and you had to physically pull them back, whilst others have been the traditional electric that we're now used to, and a handful of manual wind-backs like those found in Fords from the early 70s.