Help ID this Retro Upper

[I.Oak.47]

I cant figure out what model rifle this upper is originally for.
I see some of these uppers (without forward assist type) that the seam meets the lower receiver Flush and others (like mine) that don't.
:confused:

Colt Proof Marks: Triangle & Square with "C" Located in front of ejection port, But No Forge Code
REAR SIGHT: Raised Directional Markings
Front take-down pin is recessed for the pin type with detent? (picture below )

The 3 uppers in 1st picture are mine


http://i1117.photobucket.com/albums/k598/mobmob2/SANY0247_zpskxc0u3wn.jpg

http://i1117.photobucket.com/albums/k598/mobmob2/PivotLug-12-247x201_zpsl5ywdd4g.jpg

I found these pics online for reference
http://i1117.photobucket.com/albums/k598/mobmob2/1111_zpsuakspyvl.jpg

http://i1117.photobucket.com/albums/k598/mobmob2/styles_zpstdegx42z.jpg

[Renegade04]

From your description, it appears that they are Colt Model 604 uppers. Here is the description of the Colt Model 604 upper from Retroblackrifle.com:

UPPER RECEIVER:
PROOF MARKS / FORGE CODE:
Colt Proof Marks - Triangle & Square with "C"
Located in front of ejection port
No Forge Code

In addition, the rear sight directional markings are raised. If it were a Model 602 upper, they would be recessed.

[ClassIIIGunsmith]

From your description, it appears that they are Colt Model 604 uppers. Here is the description of the Colt Model 604 upper from Retroblackrifle.com:

UPPER RECEIVER:
PROOF MARKS / FORGE CODE:
Colt Proof Marks - Triangle & Square with "C"
Located in front of ejection port
No Forge Code

In addition, the rear sight directional markings are raised. If it were a Model 602 upper, they would be recessed.

I agree its a 604 with a great fit