What color are you looking for? I know it is difficult for some of the vinyl shops to match some of the old colors. I ordered some yellow stars that were no where near close to the OEM's.
Jim @Bay Area Water Sports had an inventory of old decals. I bought a few from him that were perfect.
I have a pair of orginal side decals in beige that I will part with for the right price. No guarantees to how well the adhesive has held up though as the decals are nearly 30 years old.
STARS AND STRIPES FOREVER