Vintage Omega 18k Yellow Gold Month Day Date Moonphase. The model of this Omega is 156.003. The case is 18k yellow gold with smooth bezel. Featuring a multi grey toned dial with month, day, date, and moonphase. This Omega is accompanied by a generic strap and original 18k yellow gold Omega buckle stamped with the Omega logo and 750 hallmark. The case is 34mm in diameter. The caseback is an exhibition caseback displaying the Omega 715 caliber. The caseback is stamped on the inner rim "MU 750 750 156.003" with 18k hallmark and Omega logo. Movement signed "OMEGA WISS ADJUSTED TWO (2) POSITIONS TWENTY-FOUR 24 JEWELS 715 37040XXX". Total weight : 51.3g. Condition: (Excellent).