Several aftermarket suppliers offer a booster with a clutch master. Check out ABS in Orange, CA. www.abspowerbrake.com.
They show the unit on page 74 of their catalogue.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine