When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Jaguar used the "4HU" differential for decades, 1960s-1990s, on various models. Not sure if the 004-25 helps narrow things down.
As for the suspension and brakes, well, it's looks pretty typical XJ6-XJS fare but I'm not expert enough to identify any minor differences that might nail down the exact original usage.
Looking through my pics the diff has the same numbers as my 73" XJ6 (series 1) . The holes in the hanbdbrake caliper arms are the same too. Everything else looks to be the same as my S1