That metalwork on that one actually looks better made than mine. As mentioned, the ring is about 41mm inside which means it has no grip whatsoever.
---------- Post added at 09:30 AM ---------- Previous post was at 09:24 AM ----------
I've never welded anything in my life I'm afraid and have no kit to do it. (I think I once brazed something in Craft Design Technology classes as school 30 years ago...) I was thinking of cutting the existing ring off the base, making a new one from 1.5" exhaust pipe coupler tube and then joining them together with metal epoxy. As mentioned, the join will be concealed when assembled.