A search for renewals for Modern Screen waa done at copyright.gov. While there are some post-1978 original registrations, none pertain to the magazine published by Dell. There were no renewals for anything with a title of Modern Screen. There's no evidenct that copyright continues to be claimed on this material.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.
{{Information |Description=Photo of Grace Kelly from the cover of ''Modern Screen'' in 1955. |Source=[http://web.archive.org/web/20140730201602/http://www.ebay.com/itm/GRACE-KELLY-JOAN-COLLINS-LANA-TURNER-etc-vintage-1955-MODERN-SCREEN-/291138374054?pt...