Looks like a length of 3/8" solid tube bronze formed into a circle, and the ends flattened and drilled. The reason I'm stripping these spreaders is the tops are in rough shape(from the sun) and need restoration .

The curious part is cutting off the tape! A lot of years here, as witness the tight growth rings. Elk hide might be a good idea. There isn't this much tape available in Rockport.

The spreaders are in good shape underneath the ravaged upper coatings(white paint over varnish). They strip off easily with a heat gun and a pull scraper with a very light touch. They're lovely pieces of clear grained solid spruce stock, over 2" thick. They're shaped like an air plane wing section. Some holes to plug, some moron drilled a couple right through the middle(right side of photo), for what reason, I can't imagine.