Looks like a Chinese knot.
I think that handle was probably turned in Europe, and the odd construction also in Europe.
Kudos to you for making sense of that comment lol
Perhaps it was hand tied in the Isle Of Man.
I agree it is a great brush and as you said it never lost a hair. What irked me is the fact that the ring was just not held on with much of glue, an outlier, probably. The ring slips easily out when the brush is wet, and I only shake lightly. I guess that the little amount of glue was not enough and it failed after a couple years of light use (maybe every 2-3 weeks)
I was going to suggest that you send it to Rudy Vey to be fixed, but you already thought of that. Looks like he did a good job as usual.
I think they simply didn't use enough glue when they assembled the ring to the wood originally. depending on the materials being glued together and the adhesive, a certain minimum bond thickness is desirable. You don't want the adhesive to squeeze out between two dissimilar materials. I am sure the pewter ring expands more than the wood with heat, and I suspect that unlike the pewter, the wood shrinks over the years. Therefore, a supple adhesive of reasonable thickness (and with good coverage which we didn't have here) is desirable. In aircraft sheet metal work, a lot of the adhesives contain precisely sized glass beads to ensure a minimum bond thickness between materials like aluminum and kevlar. One of the stronger and stretchier adhesives I used a lot on Sikorsky helicopters contains 0.005" beads, but I think you would want much thicker bonds with something that isn't so stable and precisely made, like a lathe turned piece of bog oak with a handmade pewter ring.
