Lazarus thread time- but I've had this saddle sitting in a canvas sack for almost 3 years now. That front piece is indeed a smooth rivet with a taper to it. I just couldn't force anything in and have it stay. So I drilled and punched out the old rivet, fitted a bolt of the same size, then added lock washers, a thick fender washer, and bolted it together. I put some loctite on the bolt for good measure. I then reassembled the saddle. The saddle is from the 1970s I'd say.