I would start by contacting these companies. They may have spare parts laying around or have a source for them. Daytona Parts helped me with a choke housing for my '56 Cad:
Carburetor Doctor Carburetor kits for all makes and models from 1927 to present
4107 - 50 St Rebuild services for all carbs
Stony Plain
Alberta, Canada T7Z 1L5
780-968-6622 (country code 01)
Rusty Petrovic
http://www.carburetor.ca/ Carburetor Rebuilders Co. Ltd.
4780 Fices Road
Oshawa, Ontario
L1H 8L7
Toll Free (866) 990-8114
Tel: (416) 781-8114
Fax: (416) 781-3762
http://www.carbrebuilders.com/contact.htmThe Carburetor Shop Carburetor rebuild kits for all makes, models, years
204 East 15th Street
Eldon, MO 65026
573-392-7378
http://www.thecarburetorshop.com/Daytona Parts Company Carburetor parts and total rebuilds. Helpful information over the phone to tune or fix your own as well.
386-427-7108
www.daytonaparts.com mail@daytonaparts.comAsk for Ron Hewitt or Tim Hewitt.