This mag has a Colt baseplate with markings:
(Pony) COLT AR-15
CAL. .223
COLT'S PT.F.A.MFG. CO.INC.
HARTFORD, CONN. U.S.A.
The baseplate is not blue/black, it is dull silver.

all the anodizing is off the mag,but it is not the goldish brown that is on all my other colt and UI Simmonds mags.  The anodizing is a dark greenish brown with a very smooth finish - almost looks like a teflon finish.  There is still some of the grey finish on the inside walls of the mag.

The side of the mag with the mag release hole has , on the bottom of the side in the middle, a 1/4 inch incribed (factory looks like) circle with a number "1" inscribed in it.   The follower is s dull silver.
There is not a UI/CH marking on the spine and no markings inside the mag walls.

Ever seen this dark greenish anodizing under the grey moly?

Ever seen a dull silver Colt baseplate?

What's the 1 with a circle around it?

Any ideas?  Thanks a lot.  Alan
P.S.  I don't have a digital camera

So if it is new in pristine condition, is it worth anything as far as a collector's magazine?By the way, you ID'd the same mag for me in another post. Thanks Troy!--Thomas