I just picked up a 1898-dated CG M/96 and it has a "Vasteras" sight afixed to the rear sight. I thought they were only used on some M/38's. Was it added by a previous owner or would it have been part of a standard configuration?
October 1939 came this ad in FSR magazine. Military trial had been made same year in July. So since I was posting in above linked thread my conclusion is now that the S-M-siktet (Västerås sight) was put on market 1939 as first.