I believe the bearing is installed in the correct position as far as thrust with the outer ring getting the thrust from the outside. That's the same as the outer race on a tapered roller bearing being to the outside of the differential case. Differential side bearings are usually tapered roller, not ball bearings. Although this appears to be an angular contact ball bearing.
I did find an old New Departure catalog entry with dimensions. See attached.
I looked around couldn't find a 43mm bore diameter bearing. I tried Timken, NSK, and SKF. The closest I could find was a 40mm x 80mm x 18mm 40 degree bearing (SKF 7208 series) in an SKF online catalog. That could probably be used by machining the diameter of the carrier down by 3mm (nearly 1/8".) If that's too small, a spacer could be machined for a 45mmx80mmx18mm bearing. That would be a 7209 series.
Here's one on eBay
