Munising Wood Bowl w/ metal rim

I picked up this bowl in a So. Cal. Thrift store a few years back. From what I have researched the bowl is probably a late 30's- 50's Munising. However I have not come across any other bowls that have this metal rim. I'm not certain what type of metal it is. It is non-magnetic. Not being able to find anything similar, I would guess that someone added this aftermarket - or this is some rare special edition?? Any clues are greatly appreciated!