Quoted:
Thank you all.
I too think the carry handle with the circle is strange. The "UP" - "DN" arrows look strange, and the nuts come off completely.
Ekie had a great M4 ca. 1995 gery project. He uses a grey CH with similar mark:
http://www.ar15.com/forums/t_3_118/231110_.html
Email or IM him for info on his circle A-1 CH. I have only seen pics of (5) of them includes yours. Mine is out-of-spec but it might be the exception to the rule. It also differs from yours in that the scope attachment hole in the top of the handle is round not oblong like yours & all the other Colt CHs I have.
Mike,
When you have time, attach your circle A-1 handle to any Colt flat top upper receiver and check if it fits flush with the top of the receiver.
TIA
Here is mine:
L-R: A H, circle A-1, & keyhole 8
Circle A-1 CH on early Colt C AF M4A1 receiver showing gap between upper receiver & CH. CH does not sit flush front or rear. All other USGI/Colt carry handles sit flush.