rear master-brake cylinder

my 52servi-car rear brakes dont do a lot, the brake-shoes are new, both the brake cylinders are rebuild, but now there's a leak somewhere near the brake fluid-reservoir , i also think it must be rebuild but wat are the-oem-numbers.??

MASTER CYLINDER :rebuild kit Warner REF # 8126746
:also used on JEEP vehicles 1941-66 MB & CJ models

WHEEL CYLINDER :Wagner # F40963
7/8" bore should always be replaced or rebuilt in pairs