that's just the problem- they aren't standard rings. the spacing on the mounting holes- the corner holes for mounting the rings to the body- are completely different from standard rings. I have standard Gibson mounting rings, Epiphone mounting rings, and several sets of generic rings- and none of them match the stock rings on this Artcore. also the stock rings are wider and taller than standard rings- 92.1mm wide vs 89.6mm and 45.9mm vs 44.1mm. and the opening on the stock rings are 70.9mm x 39.7mm where the standard Gibson ring opening is 70.4mm x 38.6mm.
I have not found any rings with the same dimensions as the stock Artcore rings- flat or curved for archtop, plastic/metal/or wood. I probably have 6 or 8 sets of rings collected over the years and none of them- zero- even comes close.
It's looking like i'll have to produce some myself from some of my scrap wood.
I just can't believe that with the number of Artcore guitars that have been produced that no one has any OEM rings, or an aftermarket ring that would match.