Leica 111--year of manufacture query.

[SCOTFORTHLAD]

An old workmate whose father left him a Leica 111,with the serial number 513710,has asked if I can find out the year that it was manufactured.I have looked at the list on Cameraquest,but numbers in this range don't appear,although IIIC models in the period 50/51/52 have number ranges quite close to this.Can anyone clarify.

Thanks,
Brian.