Wiley , you beat me too it, havin a "crack" about the size of your ring ...
Phantoms ring has a peened over end with less than a mm (by my estimate) gap between peening and ring base which to me suggests it was on a metal , tin if you like, type of object such as a cash draw or something.
You have a very nice ring there phantom, as big or slightly larger than the $2 coin , a finger would almost go in your ring compared to wileys ring.
Most likely a tin lid or drawer, Much easier to grip with cold fingers than a knob of that size.
Very intriguing.