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.
Wynn
USAF Retired '88, NRA Life Member. Wife USAF Retired '96
Avatar: Wynn re-enlists his wife Desiree, circa 1988 Loring AFB, ME. 42nd BMW, Heavy (SAC) B-52G's
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.”
and
"Peace is that brief glorious moment in history when everybody stands around reloading".