I consider this version of the 123 to be the most undervalued of them all. The Sievert quality before the Optimus changes. But, since it does not have the Sievert details, it sells for less than other 123s with the Sievert details. Sievert box. No engraving. No Sievert name on any parts. Twisted chain. Short key. No rings on vaporizer.
I believe that it is after the 1969 purchase of Svea by Optimus and before Optimus added rings to the vaporizer. This is well before the 123R.