Sheet Metal Bolts
I assume you're talking about the 3/8" USS coarse thread ones with the all important flanged heads ? I *think* the host here sells them , else just take them off a junker and clean up by switshing in some dilute Phosphoric Acid & water solution , they'll come out loking As-New , gotta de-greae 'em first of course .
Maybe Joe can sell you a package of them ? .
The flange head is really important as it prevents cracking of the sheet metal , unlike just adding reguklar flat washers .