Indentification request for Mitchell wide angle adapter?

I am hoping someone here can identify a Mitchell lens based upon help
supplied to others. I literally inherited it.

From what I can tell, it is an afocal wide angle adapter. I estimate it to
increase the field-of-view by a factor of 1.5. The only identification is on
the farthest out barrel cylindrical surface.

MITCHELL
NO. 1005

I do not know if the number is a part number or a serial number. The major
diameter of the mounting thread is 1.83 inches. That converts to 46.5 mm.
Weird.

Thanks.

Bill