A buddy of mine just came over with an SP1 that he bought over the net. It appears to be all Colt parts but the upper receiver is black while the lower is typical Colt gray. I've seen quite a few SP1's but never one with a black upper.
Have any of you guys ever seen one like that???
TIA

ColtShorty

GOA KABA COA JPFO SAF NRA

"I won't be wronged,  I won't be insulted
and I won't be laid a hand on. I don't do
these things to other people and I require
the same from them."

Just to narrow the possibilities down some, does it have a Forward Assist?

No forward assist or shell deflector. A1 sight, the lower was made in 1978, the carrier had FA notches but IIRC that was not uncommon in that time period.

ColtShorty

GOA KABA COA JPFO SAF NRA

"I won't be wronged,  I won't be insulted
and I won't be laid a hand on. I don't do
these things to other people and I require
the same from them."

Dug out  my old SP1 carbine upper for comparison so this is the best can do for you (as my knowledge of markings and indicators for AR's is limited). BTW, my SP1 is an '84.
On the barrel it's punch marked 'C MP Chrome Bore' at 12 o'clock. On the front sight base on the right side as you are holding the rifle normally there is a little nub of metal directly below the Front sight, a 'C' is part of the casting on that little nub. On the rear section of carry handle directly below the A1 windage knob (on the right side- again as above)  'C  H' is cast into the hollowed out area. The color on mine is a medium-dark charcoal grey, barrel and upper receiver are a perfect match in color as is the lower, FWIW. Hope this helps.

PS- forgot to mention my bolt carrier has the forward assist notches also.

One of the three Sp1s that I have has the black upper and grey lower. It is an 82 vintage.

Thanks guys!!!

Anyone else [?][?]

ColtShorty

GOA KABA COA JPFO SAF NRA

"I won't be wronged,  I won't be insulted
and I won't be laid a hand on. I don't do
these things to other people and I require
the same from them."