Can anyone identify my rear differential? 8 3/4 but wrong markings???

The 8 3/4 rear came out in 1957, the early rearends had axles that were different than the units of the 1960's and 70's. My Dad's 57 Dodge Custom Royal Lancer has one. Most people don't fool with the early 8 3/4 rearends.

https://www.forbbodiesonly.com/moparforum/threads/chrysler-8-3-4-rear-axle-swap-information.7702/