Sharps Mule ear case

This was also in the boxes of loose cartridges.
OD of case mouth 10.37mm=.408"
Rim dia; 11.69mm =.460"
OAL ; 27.63mm -1.087"
ID of case mouth; 9.1mm - .355"
.36 Sharps “mule ear”?

There are a number of fakes of this cartridge, but from what I can see it looks correct. Most fakes were made from .38 Revolver rounds, so look inside. Do you see solder on the outside at the base?
Mine has close to the same measurements as this, but the case length of mine is only 1.075".
Suydam pg 50 hows three variations he doesn’t say which is which but notes two of the three shown are fakes.(two on the right) A base with the ear is soldered onto the base. A real one has the same construction yours exhibits, from what I can see…

No solder anywhere

Interesting. Any chance of a photo of the area where the lip meets the case under the rim to see how / where it attaches to the body.
See the arrow on your photo

Another view of the area in question.

The grime/patina appears to have been there a long time?
Pete here is a better view of the area in ?

I have in my collection this .36 Sharp Mule Erar. In theory is original, I hope opinons…36 mule  ear