I have a series 70 Nickel Combat Commander.  It has a blued thumb safety and a blued barrel.  Are these parts possibly original to the pistol.  My brother bought it in the early 80's.  It was mfg. in 1974.  Just curious.  I am searching for a nickel saftey release, but if blued could be original, I want to leave it that way.  It just does not look right.  Here's a pic, well, how do I add a pic?

Colt made 'em both ways...I have seen several like you describe as well as many more with everything satin nickled.

I had a few full sized series '70s where the frame and slide were nickeled and most of the other moving parts were blued...I don't recall the slidestop not being blued too. [:\]
I think the barrels were completly nickeled too, including the chamber/hood area.
Nickeled parts are getting harder to find, usually only in SS or blue anymore.
I understand you want to keep it original, or maybe just a blue slidestop would "balance" out the look.
The majority, if not all, Commanders I remember seeing in nickel, were done in total nickel, but the full sized model, having had a few, I do remember being "peppered".