His Lordship (1932)
The commoner is a happy cockney plumber by the name of Bert Gibbs. Bert comes into contact with the celebrated Russian movie star Ilya Myona. Desperate for publicity and aware that nobility make for good copy, Ilya persuades Bert to pose as her fiancé (with the possibility of persuading him to go through with the marriage if need be). Things are complicated by a pair of anarchic Bolsheviks, one of whom has a daughter named Lenina who knows Bert from his plumber days and is quite in love with him.
