1. I think the fuel tank mounts are different, body mounts are almost the same, rearmounts go inside the body instead of outside.
2. I dont think you can modify the shifter easily, engine should be okay.
3. I have a disco front, used the 110 calipers on it, I will be converting my rear salisbury to disc. The disco rear may not be strong enough, later 110 have an uprated version of it.
4. B pillars are available, I believe the crossmembers are on back order currently from someone elses post recently.