Quoted:
I have an XM177E2 and 607 kind of long term projects going but I want something now so with what I have a 623 fills the retro and KISS bug all in one shot and much sooner than later

I have not gotten up with pics yet but here is what I have:

  CH marked C7 upper
  SP1 carbine barrel assembly with 6 hole colt hand guards
  Colt two position buffer tube and hardware
  Fiberlite N1 stock (I also have a colt aluminum stock in about 85% condition)
  Anderson 80% lower (unmarked or contoured)

My questions are:

  Would the delta ring be more the early gray color or the later darker gray/black:

It would have been gray AFAIK
  Would the bolt carrier be a C marked with large or small FPRP hole
Pretty sure it would have been small
  I noticed on many pics that he lower receiver had A2 reinforcing at rear but the earlier profile around the front pivot pin area. What is the most correct/common lower profile
On a later rifle with a C7 upper it could have been A1 or A2 or possibly a variation of the two, choose which you like best.
  What would be the correct lower receiver markings for a 723
Honestly, I have no idea, sorry.
  What would be the correct pistol grip?
The A2 would be the correct grip.

I really appreciate the help.

Travis