So quite a while ago, I ground off the rear tang on my MAK90, when I reconverted it back to an underfolder.  I ground off the tang, and left it as is, with a quick cold blue job.
Now I've been refinishing it, I've gotten the area(rear trunnion) nice and smooth now and to a polished(mirror) finish and am looking at doing a nice cold blue job on the area.  I like what I'm reading about the blue wonder cold blue kit.  But I don't know which would match the rifle better.  Their blue kit or their black cold blue kit.  The rifle has the standard Chinese blueing.

Any suggestions on which would match better?

Went with cold black.

Post some pics please, I would like to see how it looks. I'm going to need to re blue mine down the road....