Duff,
The rifle maker - Zastava,
Sporting rifle M70 Standard | Zastava-arms - was founded in 1853 and has been making firearms continuously since then. The factory is located in Serbia, which used to be part of the former Yugoslavia. Remington imports the barreled actions from there and the stock is added in Kentucky.
There are some aftermarket options for this rifle, including rifle stocks and several scope mounting choices. Triggers are available through any supplier such as Brownells. These rifle are now being handled by Century Arms.
This model M798, is originally traced back to Belgium (1947/48) and has been referred to as the FN Improved Mauser M98 action. The most noticeable change is the thumb notch removal from the left side of the action leaving a solid wall.
The barrel threads are the same 1.100 x 12 tpi (55 deg) and are available as blanks (obviously) or threaded short or long chambered from various suppliers. Scope bases are standardized with some good designs from Ken Farrell (
Ken Farrell, Inc. -- Rifle Related Products) and the triggers as I mentioned are from several manufacturers including Timney.
Regards.