Depends on if you are concerned with it looking original....
If you don't really care, you can use a regular pop-rivet to hold it on. Prolly need to get long shank ones, like maybe a 5/16" or longer.
If you want it to look "correct", the only option is to get the original type rivets, and either buy/borrow, or fabricate bucks to mash them down....
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Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"