As the poker game progresses, Baker strips to his undershirt, but when Radar looks at him through the telescope he's still wearing his outer shirt.
Near the beginning of the Poker game. Radar is seen looking through the telescope from the shower. Later when a nurse walks in front of Radar he follows her till she enter the Shower. There is only one Shower room located at M*A*S*H.
When Baker first arrives he addresses Hawkeye as "sir" and salutes him, although Hawkeye wears no rank insignia to indicate he's an officer.