Long post, sorry -
Biggest hurdle of using the complete Caprice roof is the rear grab handles. If you use the Caprice side trims, the handles will be in the wrong spot and you'll have to cut your metal part of the car roof. This is the reason everyone grafts the centre of the Caprice roof lining onto a standard sedan roof.
I went the "cut the holes in the metal roof" method in my old VN. Was very messy and had to get stainless steel brackets made up to accommodate the new mounting hole locations and entry for the light in the handles. Went LED for size issues.
If I had to do it again, I'd retrofit the Caprice goodies to a standard roof panel from a VR/VS - as they are thicker than a VN/VP roof lining.
I know you've said you've made it fit - but how well? Just asking as this would be the chance to do it from scratch.
Getting one that's been in a sedan with a sunroof is hard. Its almost a "custom" job to add a sunroof cutout to a non sunroof lining.
Finding the centre roof brackets (factory) from a Caprice with a sunroof to retro fit into your sedan will be a mission, unless you have the entire Caprice to strip. Otherwise the mirrors in the head lining will be very flimsy to use and the whole roof will wobble, especially if you plan to retrofit an LCD screen in there.
Buy the cheapest, thinnest and most Asian screen that's around 5.5/6" because your going to strip them back to almost nothing to get them to fit. Flat computer ribbon cable is what i used to get power/signal to them as everything else was too thick and prevented the mirror case from closing properly. Cat 6 was a nightmare as the closing mechanism eventually broke the wires inside the sheath.
If you do install screens, be prepared for a lot of fine soldering, fitment issues and signal loss issues from the small size of cable you have to use so the damn things can close. I'd also advise some sort of power cutout switch up the front so the screens can be turned off manually, because if your relying on the factory type of power cut on the metal rods on the side of the mirrors (the way the lights know when to turn on/off) - your gonna run into issues with it not always cutting power to the screens and draining your battery.
Post up some photos of how your currently got your roof installed, and I can give you some pointers, as someone who's already tried what you've done (minus the sunroof) and failed , then gave up and sold the whole car just to be rid of it.
