On grill, Pop Rivets! aluminum ones wont rust and run down on paint. I don' care about orig, can't see them w/out bending down/looking in good light! As for frame rivets, I use good hard 3/8" bolts. Best kind have the washer heads and lock-nuts, but can cost big bucks. Ace Hardware and others have them in little box drawerw of special hardware, not many in stock at once. Or good Gr 8 bolts. Problem with most rivets is how to collapse them. little ones need hammer and special back-up tool and usually cant get into part to do that. Big ones used hydraulic press in plants, can't do that at home and heating and pounding on them seems futile.