...make sure you got accurate scans of the correct size for repros before you scrap the old plastics...

 Those rivets in the picture, are mushroomed over the steel bracket. If you use a Dremel tool with a grinding wheel, and take it slow, you can grind the mushroomed part off, and the pieces will seperate.
 Don't try to use those Canadian Tire rivets, sometimes they will put alot of stress on the plastic when compressing the rivet, and crack the plastic.
 You can buy old style rivets, at any good fasterner supplier, and replace those.