13a Jack Frost came in disguise...as the other fellow (6) I?e?a?
44a Oh dear, deer go head to head(3) ru? ~ I am getting the U from 45d What should be numbered between twelve and twenty imply doesn't figure! - Umpteen
39d Both he and she have it down to a T (3) Pa?
Pat - Idioms by The Free Dictionary
have (something) off pat. To learn, master, or understand something perfectly, ... learn (something) down pat. To learn, master, or understand something perfectly, ...