Diff stamping?

[tbomachines]

I suspect the diff on my 300E is not stock but somewhat taller than stock. This would explain a ton of oddities that I've noticed:
- sluggishness off the line (created thread)
- Seemingly impossible highway gas mileage (created thread, 30+mpg)
- Speedometer being off (reads high below 60 and low above 60)
- Odometer being off

My car has a strange and sketchy past so it would not surprise me to learn the diff is different (no pun intended). Is there a stamping anywhere on the housing of the ratio? I guess a part number would do too--and then look up the MB number, or is that just for the housing? I didn't see any numbers on the diff but it was getting dark out when I crawled under there. Any help appreciated - thanks!!