I thought about the rattle when I did mine, now I did not wrap my own baffles they are the short ones speedway sells. The wrap was thick enough to take up any space. I have them in sprint style headers with 20 inch kick outs.

Going on 3 years now, the car weather considered goes on the road weekends. Driving not parking so plenty of heat cycles have worked them over so far so good. I think the steel rivets work with the steel in the baffle better then the aluminum ones, all in all I like the method you came up with.