The latch in front of the trigger guard is the take down release latch. You will see that the rifle does not have an action screw in front of the magazine.

The rifle can be taken down as follows

1 Remove the rotary magazine.
2 Unscrew or pop out the bolt in front of the sling swivel which locks the barrel band to the stock (My rifle has a stirrup type sling holder that is held to the stock by this bolt.)
3 Turn the latch in front of the trigger guard - your bottom photo is the open position (I think

).
4 Pull out the barreled action from the stock carefully! The tang fits neatly under the peep sight assembly. In models that do not have this peep sight (like my 6.5MS), the tang fits a bit under the wood.

Good luck with your project.

PS I tried my model 1910 9.5X57 MS yesterday. 3 rounds at 35 meters were 1 inch under the bull's eye with open "V" sights.