here shock...Sorry man I can't give you the specifics on the material as I'm not a nitro person..but I have made people clutch bell washers from shim stock I had laying around...
I just did a quick look and found a few clutch bell washers both steel brass and fiber . also found a 20 tooth traxxas clutch bell with 20t gear.do you have any local hobby stores open by you? mine have a few racks of parts from screws n nuts to washers...fabrication of parts has always been my...