I'm very sorry about your loss. I understand that you want to keep the integrity of your brother's ring. I have this stuff called ring guard from ebay that I use. It's liquid silicon and very comfortable and easy to use. I'll include a link:
i got some of those ring sizer things from claires that a few of you mentioned and ordered some of the others....they're all pretty inexpensive so i'll play around and see what works best. i've been able to wear it since last week courtesy of some althetic tape...the plastic things from claires work much better. thanks again!