I just cut unsightly stuff off... carefully. I also had buildup of plastic compressing behind the barrel lug that I trimmed and got out of the way before it hindered operation.
There's a half cylinder "skeleton" of steel embedded in the front of the frame with the rails protruding... and yes, there's a little "nick" in the left one for manufacturing alignment... on most models, anyhow. The rear of the frame has two smaller rails, so the slide rides on steel, front and rear.
USAF Retired '88, Wife USAF Ret. '96
Avatar: Mag-na-ported Kahr P40 firing WW100 165-gr FMJ
Frédéric Bastiat’s essay, The Law: http://mises.org/books/thelaw.pdf
Thomas Jefferson said
“A government big enough to give you everything you want, is strong enough to take everything you have.”
"Peace is that brief glorious moment in history when everybody stands around reloading".