No way. I understand that it hurts to see the ring off (and it hurts me every time I look at my H's naked hand as well) but you are trying to control her and whether she wears her ring. Leave her to her journey. The way you frame it seems like "I'm going to take my ball and go home." I know it's hard but try not to be petty or do things that force her hand. Leave her be. Let her find her own way.... As a W, it would totally anger me if my H asked for the ring back. I'd say, "WTF are you kidding me? It's my ring and I get to wear it or not. You don't have any say in that. Even if I don't wear it, it's still mine. Back off jack." So, to my mind, nothing good could come from you even talking about it. Pretend like it doesn't bother you on the outside. That is bound to get more interest from her than the other approach.
