I couldn't tell you the exact model but it's a Druggi, and they all come apart and go back together the same way. You're right in that it follows the RPK design more than the Kalashnikov but they really aren't all that much different.
Depending on its age and use you may find your best accuracy with 7.62x54R hunting ammo from Wolf, PRVI or S&B. Order a bunch but see what shoots best first.
If you can find a few more magazines without having to sell off half your children, stock up.
That Dragonov will discourage that old buck very nicely, maybe even as far out as 400m. You are fortunate to have come by the Druggi. Use it well and remember your buddy.
