just sold a new style end can , no rivets !!
Probably not what you want to hear , but you'll always have problems with the rivets becoming loose.
£50 for latest style ones I think and are a tad quieter.
No nails .....lol
self tappers mmmm..
Only new out so time will tell
The only sure fire way would be to have captive nut and bolt arrangement imo, but wether or not there is room for the nuts inside the tailcan ?
Strip it all down after marking the sleeve and end caps for realignment and use M4 stainless button heads and nuts. Pass the bolts thru the end caps,fit nuts to the inside and weld on.Use locktite on assembly and when the wadding needs changing just remove the outlet end cap