Sperry Marine MK-37 Mod D/E gyrocompass set for sale This offer is for Sperry MK-37, Mod. D/E (PN 03956-1891974-1) Used Marine Gyro Compass complete set for sale. This master gyrocompass comes with control unit & transmission unit PN 03956-1979820 and two analog bearing repeaters. Set is in fully working condition and…