Where did you come up with gold trigger meaning limited edition?Gold trigger represents a "Limited Edition".
As stated above, look for the JM stamp. It would be located on the left side of the barrel just in front of the receiver. It's a small stamp, and not always clear, but it will either be stamped JM or REM.
The JM stamps command a higher price.
The only stamp I see is a REP inside and oval with a S just to the right of the oval.