Chief Dooley says his wife had an affair with some guy from Hoboken that was 4-F (graded unfit for U.S. military service). Frank Sinatra was from Hoboken and was 4-F.
While Chief Dooley is talking to Dr. Ivchenko, discussing his marital issues at home, he says his wife's lover was classified as 4-F (a US military classification, deeming candidates unfit for active service). This was the same classification Steve Rogers was given several times upon his attempts to join the US Army before becoming Captain America.
The jeweler says the Stark Special bracelets are made from "the highest karat gold." Pure gold, 24 karat, can be made into jewelry. However, pure gold is so very soft that it would never hold up to the stresses of normal wear. The 18 or 14 karat gold normally used for jewelry has been alloyed with harder metals like silver.
Chief Roger Dooley asks Dr. Ivchenko if they have King Kong in Russia. Shea Whigham, who plays Dooley, went on to co-star as Cole in Kong: Skull Island (2017).