Mary tells Harry that the raffle was Billy's idea but it was actually Nicholas' idea.
The film setting is 1954 but most of the cast members are wearing late 70's hairstyles/facial hair/clothing/slang that wasn't in style in 1954.
The Orioles cap that Mary wears in the film has an orange bill. The Orioles didn't start wearing Orange bills on their caps until 1958, four years after the setting of the film takes place.
The Orioles pennant in Amos Jones hot dog stand is the modern (1979) logo and not the correct 1954 logo.
At the hospital Andy is wearing an Orioles cap with an Orange bill. The Orioles didn't start wearing Orange bills on their caps until 1958.