https://www.answers.com/collecting-hobbies/What_is_the_value_of_a_1924_US_20_dollar_Accugraded_ms64_gold_coin_Philadelphia_minted
What is the value of a 1924 US 20 dollar Accugraded ms64 gold coin Philadelphia minted? - Answers
Break it out of the slab and have it graded by a reputable service. It probably does not deserve an MS64 and may not even make MS60.