This is a Smiths General Service (GS) wristwatch which was issued in 1961. This is the rarest Smiths military watch since this is part of the small batch that were produced for the Australian military in 1961. The overall production number isn't know, but there are approximately 20 known examples that have surfaced and the number spread runs from 155 to 556. Assuming 3 digit numbers were used this would possibly indicate an order of 500 pieces. 

The case back engraving gives the NATO item code for a "Time Measuring Instrument" (6045) and the country code for Australia (66). It also gives the unique number assigned to this particular watch (257) and the year of the order (1961).

The watch is all original and in simply outstanding condition. The and handset have the original radium-based luminous compound (please note that this no longer creates a glow in the dark - the luminous compound had a relatively short lifespan before it was exhausted). The case is in great condition - the odd rather small mark, but no major chips or signs of misuse.

These watches are very similar to the Smiths 6b/542 watches produced for RAF pilots and navigators. There is a small difference in that the movement on the Australian issue watches also hacks, allowing time setting to the second. The balance spring on the watch has a Breguet overcoil, something Smiths very rarely produced, which helps with precise timekeeping across different positions.

The inside of a plane cockpit was a fairly harsh environment for a mechanical wristwatch due to the presence of electromagnetic fields. These watches are shielded from electromagnetic interference by an iron dial and mumetal dust cover, which form an effective Faraday cage to prevent electromagnetic disturbance.


The movement has been fully serviced and is running superbly. The watch is fitted with a recreation of the AF0210 type strap, a precursor to the ubiquitous NATO strap which is found on Military watches.


Specifications:
Case diameter (excluding winding crown): 35mm
Case material: stainless steel
strap width: 17mm
time keeping: grade A