This ad ran on October 31, 1965.
This ad ran in October, 1989. They used to carry all sorts of cool stuff.
uh, yeah, totally plausible scenario!
Halliday Clark is a Man of Responsibility.
A little history from Wikipedia
"Carte Blanche originated in 1958 as a rebranded Hilton Hotels travel & entertainment card. Hilton sold Carte Blanche to First National City Bank in 1966. Regulatory challenges forced First National City Bank to sell Carte Blanche to Avco in 1968. In 1978, Citicorp (parent company of First National City Bank which was renamed Citibank) would reacquire Carte Blanche without regulatory opposition. fThe 1960s & 1970s-era Carte Blanche card was considered more prestigious worldwide than its competition, the American Express and Diners Club cards, though its small cardmember base hindered its success. Carte Blanche also was the first to implement a "Gold Card" program,but initially only as a means to recognize cardholders who were frequent users and paid their bills on time. In 1981, Citicorp would also acquire the Diners Club card and brand, and by the mid-1990s the Carte Blanche brand was slowly starting to be phased out in favor of Diners Club."
tl;dr - they were soon part of the same company/bankgroup: Diner's Club.