Your friendly local auto parts store. Don’t take their word for it! In my experience 90% of the parts counter people do not know what a Studebaker is…they will ask "Who made the car?"
At least, 50% of the time their computer parts records do not give enough information to discern between parts models and options. Take the old part you want to replace into the parts store for an eyeball comparison with whatever part they may have in stock.
A good reference site for new replacement parts/interchange info is Bob Johnstone at http://studebaker-info.org
Support your Studebaker parts vendors, they usually know what they’re talking about!