Sorry for the poor picture.
My Remington 870 ejector rivets are raised on the left side of the receiver. Not cracked or separated, just looks as if the finishing was not exactly as it should have been.
I have run about 100 rounds through with no problems.
Any cause for concern in anyone's opinion?

As long as your ejector is not loose inside the gun, you should be ok. The rivet is a 2 step creation to hold the 2 parts of the ejector. Sounds like your ejector has been replaced at some point. The outer end of the rivet is made deliberately tall and must be cut down to surface level and it appears that someone didn't do the job correctly.

No ejector replacement here, I bought it from the guy who bought it new, it came from the factory this way.
Anyone ever seen this before?

I have a express just like that, looks the same. Just a matter of budget metal finishing on a budget shotgun.

Can,t say I ever seen that before,Seen alot of 870s and mine had no poor finnish like yours.I.d be abit pissed if it did though. :(

Keep lots of oil on it. Mine would rust in the gun cabinet while well oiled. Some of the early 870 expresses were not finished right and the finish both comes off and rust badly. Had to do with not dipping the finish long enough in some solution long enough. I have a later one made last year in 20 gauge that is much nicer than the earlier ones. Like KciH said this is the bottom of the bucket for budjet guns. I finally sold my 12 super magnum express. Think I'm gonna spend the money and replace it with an over under or nice side by side.