PAVILION, SELSEY. How an artist's model seeking to solve the mystery of several murders eventually uncovers "THE MADONNA'S SECRET," is told as the leading attraction on Monday for three days. Francis Lederer is seen as the noted artist who attracts Gail Patrick and Ann Rutherford. A fine story, unrivalled cast and first-class direction are some of the factors which make "LONDON BELONGS TO ME"—showing for the remainder of the week—a notable picture. Adapted from Norman Collins' best-seller, it follows the inhabitants of a typical London boarding-house and their reactions when one of them (Richard Attenborough) becomes involved in murder.