I'll ask Lazy Ferret what his rear ones look like, they may be solid I just presumed the same as the front
The rears are hollow as well, just the same as the fronts in your picture...
I think Rick may be confused, as I didn't think he had any T1's, and the Dash board is completely different to the T2's.
When I got ours, someone had hacked the centre part of the dash about to fit a radio and CB, I had to fabricate all the bottom section myself.
I have only needed to do an oil change on ours, as the rest all looked nice and clean, so I have no practical ideas on volumes, and the manual only covered the 2.4, and 3.0 engines, so I have to use the WD21 manual for Body/electrical info, and the R21 manual for engine related info. Not sure about the gearbox though, as again, so far I have not needed to look into anything relating to that.
The Manuals I have are the same ones Briggie has in his manuals section, and when you run the EXE, it unzips them into PDF's, but there are about 100 files, and 60Mb of info, so posting them as PDF's is not very practical.
Manual says
Transfer gear oil 2.2L Dexron II or equivalent
Auto trans fluid for the 4wd is 8.5L Dexron II or equivalent
Power steering fluid is 1L Dexron II or equivalent
Diff carrier gear oil Front varies dependent on actual unit 1.3L to 1.5L API GL5
Diff carrier gear oil Rear varies dependent on actual unit 1.3L to 2.8L LSD GL5
I don't know of any breakers, I did use one of those find-a-part web sites when I wanted the rear spare wheel carrier, but other (New) stuff I have looked out for all had to come from New-Zealand with silly money shipping, so can't help much on that side of things.
Hope that helps.