I've never seen anything like that mother of pearl stem . If it's not too much trouble , could you post a pic of it w/the bowl attached ?
It's a style called a kalmasch, mid to late 1800s I believe? In an amusing coincidence, I have worked on two of this pipe - my husband bought this version (which was an absolute mess - another adventure where the stem broke and someone dumped a terrifying amount of superglue into it to try to hold it together instead of fixing the pieces and gaps individually) which I patched up.
His friend then shared a photo of the exact same pipe he had purchased a few years before and asked if the mother of pearl pieces were loose on my husband's too and decided it was kismet. Despite my insistence that I am a self-taught hobbyist, he sent me the stem to fix up too and a pair of meerschaum earrings as "payment" so you'll see in the first photos I posted I kept more of the patina on the copper as he liked that look better than the polished copper seen here.
I only just started taking "before" photos of my work this month as this was just something I've been doing to help my husband, but it's really nice to be able to share some of the fixes I'm proud of!