Complex sentence: While ill with an ulcer and busy filming "Blowing Wild" in 1953 in Mexico, he wasn't present to receive his Academy Award in February; he asked John Wayne to accept it on his behalf.
Split into simpler sentences: While ill with an ulcer and busy filming "Blowing Wild" in 1953 in Mexico, he wasn't present to receive his Academy Award in February. He asked John Wayne to accept it on his behalf.