Unfortunately the brake and clutch pedal shaft isn't being reproduced. Good news is it's the same part found in ALL 1947-55.1 (1st Series) Chevy and GMC trucks, except for Dubl-Duti (Forward Control) and COE models.
It's listed in a Chevy Master Parts Book as GM# 3683044 Shaft, clutch and brake pedal (1" x 7-17/32" 3/8-18thd)
Suggest you post an ad in our
Truck Parts Wanted forum. Fellow Bolters that may have converted their truck to firewall mounted master cylinders and others with possible extra's from a parts truck may be able to help you replace it quickly.