My father bought a Sako action back in approx. 1988-1989 for building a custom rifle. On the left side of the receiver it says AV Ser# 609979. That's all it says, no designation of what action it is. He put a Shilen barrel in .280 Rem. on it and a very early Bell and Carlson stock which I hate. I'm wanting to change the stock to an HS Precision https://www.hsprecision.com/shop/stocks/pss/pss056.html but they only list making stocks for an L691 action. From the actions listed on Wikipedia and dates of manufacture as best I can tell my action is an L61R. Can anyone confirm by the serial number what action I have, and do you know if the stock fitting an L691 would also fit an L61R? Differences between the 2 actions? Sako doesn't make it easy to find out this info. and of course they have no phone number listed on their site for contacting Sako except the number for Beretta, the current importer. Can someone please help to clear this fog of confusion? Thanks for your help.