The 26590 motor seems to have been used on HMV/Columbia pairings of machines from around c 1937. My HMV 97C has one so I would assume the Columbia vesion, the 204, would have been similarly fitted. Also the Columbia 211 and HMV 88. Both my motors are stamped 26589 for some reason I am still to discover. None of my reference books make mention of this.
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Side winding, single spring motor.
HMV 88; HMV 97C and D; some Columbia 204's and Columbia 211
NB. Should you ever strip one of these motors down work on the bearings one at a time as there are no location grooves etc on the bearings for the governor arm. If you remove both bearings life will be tricky when it comes to setting the speed later. Leaving one bearing in position while working on the other allows the correct governor arm position to be maintained. Remove the bearing that protrudes the most through the pillar. This will allow the governor to be removed. After cleaning replace the armature and bearing and if necessary remove the bearing from the other end for cleaning. Note however that some minor adjustment of the bearings will be required to create a little play in the shaft but make sure the bearing that is adjusted is the one at the opposite end to the bearing nearest the turntable spindle..