I have what I believe from research elsewhere is a Davidson Large Purple Cloud Glass # 9421 ...... but it has three peweter mounts around the rim. Haven't seen this elsewhere - so is it usual, and was it applied by Davidson or afterwards ?
The mounts only just curve under the rim and, having looked from the underside with a loupe, I can't see any damage they may be trying to hide !
Plate dimensions: 1.5" height / 11.3" diameter
Any information or ideas appreciated.