Danger: Diabolik (1968)
Diabolik appears in one of the spouse's reveries
The USA title, Danger: Diabolik, is featured on a Times Square theatre marquee.
At the end of both films, a character is defeated by being covered by molten gold.
the film is discussed in this feature
Diabolik is the featured film in this MST3K episode.
DVD release reviewed + footage used