I picked up my 4 slave and a master cylinder for my 49 from NAPA a few years ago. The slave cylinders were on the shelf and they had to order the master. Also got my shoes there.
NAPA stocks a lot of parts for old vehicles. Don't count them out.

1949 Chevy 1/2-Ton
"Sedgewick"
In the Gallery
1989 Caprice