I had a 73 model with the factory fitted metal sunroof That i restored.
i sold it about 8 years ago.
if you go onto the kombi club website an search it youll see all the pics and how the sunroof works.
you can buy second hand parts for it off the samba in the u.s.a.
A lot of the parts for the roof are not repo made and are expensive and hard to get.Any new parts made are available such as new cables and cogs from
www.eis.com (economy international).
Its very hard to get the roof too slide well with the cogs and cable setup with the goldie winder.
Even though the poptop hole is the same as a westy one the sunroof model have a metal pocket for the sunroof to slide back into inside the ceiling.
It also has 6 drainage holes for the water to drain out of which runs out under the car from the b, c and rear pillars.
So theres a lot to them and hard to get a good waterproof seal.
cheers chuck