[Milsurplus] Crypto device

[Radioman390 at cs.com]

I have a mystery gadget which I believe to be part of a decoder of a crypto 
set:
Markings on package:

CE-95029A  Grille Assy B-1
DA49-170-SC-2437
R.C. Allen Business Machines
Mfg/Contr
A-IA8-7/58.

The envelope has a date on it of  5-1957 so this might be late Korean/early 
Nam era.

The package was obviously hermetically sealed, with copper on inside of soft 
envelope, which contains a hollow cylindrical tube about 1.5 in long and 1 
inch dia.
At one end is a gear with 26 teeth, and up and down the walls of the cylinder 
are slots of various sizes and orientation (all are rectangular).

I very vaguely remember (imagine?) a projection encoder which has prism-like 
rods that went up inside the unit, and then were reflected out. I assume these 
slots allowed letters to shine on translucent windows, and that the slots 
equated to rotor settings.

R C Allen made typewriters, so this might be an office machine part....more 
likely they built a crypto device.

Can anyone provide more info?