Colonel Hogan (Bob Crane) tells Kommandant Klink (Werner Klemperer) the cuckoo clock in his office is a Hammelburg (Germany) antique clock. A cuckoo clock is a typically pendulum-regulated clock that strikes the hours with a sound like a common cuckoo's call and has an automated cuckoo bird that moves with each note. It is thought that much of its development and evolution was made in the Black Forest area in southwestern Germany.
It was stated that the clocks sell locally for 10 marks, the equivalent of $3 and some cents. This would be an exchange rate of 3+ marks to the dollar. According to Google it was a bit less more like $2.50. But $100 in 1943 would be worth approximately $1,739 in 2023, just for comparison.