I have an estate Karl Eric pipe with a bent, saddle stem. The stem has a mark like a Z with a small, solid white triangle right behind that. It does not look like the Karl Eric mark (or even remnant of it) listed in the pipephil.eu. I am going to guess that it is a replacement. At any rate, the stem opening seem constricted all the way through the length. Draw is moderately okay, but it can get plugged fairly easily even with lint from a pipe cleaner. Is there a fool-proof way (for an idiot) to open it slightly?