This is the other side, I've found many broken ones, usually mud color, only have 2 wholes ones, both the red clay color. That collar piece looks familiar, have to go thru the scrap pile.That site produced some first for me, the pewter base, an opium pipe, and square soy sauce pots,a nice white one and a tan one,whole,unbroken.Maybe the user had to modify it for use,reversed,made the opening larger to fit on pipe?original side for collar looks like inside of hole was being scraped to make wider but other side easier to make larger? I was guessing about the base being pewter, white brass sounds good to me.