The CWC serial numbers ending in ACw run from about mid 1949 through the end of 1951. The "H" puts your bike toward the end of that period. Most CWC bikes ran inch-pitch chain through 1953 but some were equipped with 1/2" pitch as early as 1941. As noted, Roadmaster was the house badge and brand but they were sold by many different retailers under many different names. Unless the bike has brand specific sheet metal or there is a unique badge ghosted in the paint it is next to impossible to know for certain how the bike was originally badged.