Ive just been researching this motor.
It is a Mabuchi RS-555SH-20120. Link to page decoding Mabuchi motor codes:
The first 2 nodes of the code give you all the physical characteristics, except shaft characteristics...which oddly are not included anywhere in the coding, but there are in fact a number of variations.
The last node is winding specifications. I have not been able to find the 20120 version, not even on Mabuchi's site (may be a custom winding for Caframo), but Im searching for other winding versions which would result in a similar speed.
You can find variations on the this motor on ebay.
This listing has the correct shaft lenth (19mm), but is a D type shaft, not a round shaft. Winding specs are not given.