John's stud experience remains an anomaly. I haven't first hand knowledge with a '49 then again that wasn't the question posed so not really sound advice for Ricky's '62. I do know late-'50s to early-'70s well enough to write on this subject.
If CC studs were readily available, they would not have been brought up countless times over last few years on numerous hearse forums by many people looking. Each has had the same problem not being able to locate
exact replacements. Christin likewise would not have gone through the effort to have them machined if NAPA had them in stock.
If you have a friend at auto parts store, take a stud and start matching up behind counter. You
can find many nearly perfect length, shoulder, threads and knurl that will match. Head on CC wheel stud is 1 1/8", much larger than the rest - which is the difference. Lay a dime on a quarter and you'll have an idea is size disparity. A friend with a '62 (same year, CC will all remain same regardless of coach builder) MM also found this out.
One can make a valid point stating that if the knurl remains tight a smaller hardened stud head would not pull through a hardened axle. Not a risk I personally would take. They were designed differently for a reason.
Another '73 hearse owner finally gave up after searching and searching. He figured out (with a micrometer and axle in hand) that mid-'70s Chevy trucks had 3 1/2" studs with a large enough head. Using them necessitated drilling slightly larger holes in drums and spacers, then cutting studs down to fit hubcaps. Can probably get a parts number from him if needed.
So as stated, not as easy as going down to local store and finding
exact replacements. There isn't enough demand for CC wheel studs that they're currently made en mass. If you do happen to find some old stock - buy them! All.