Newton had some of his rifles made on contract in Germany on 98 actions.
Some of those had the reverse facing front trigger in the DST style as shown.
The German made rifles had the much nicer made triggers with trim profiles.
The US made Newton reverse style DST used on the 2nd Model Newton rifle have the very heavy profile triggers as mentioned above.
The US made (Buffalo, NY made or 1st Model Newtons) with the standard looking DST system (both triggers facing forward) have trim profiles as well.
They are coil spring powered.
I'd guess that the trigger on the rifle is German and the style Newton ordered for his rifles. Newton ordered commercial Mauser 98 actions to be used AFAIK.
Added
Scroll down a ways in this link and there is a pic of the 2 different US built Newtons and one of a German made Newton.
The latter has the style of DST in question.
https://revivaler.com/newton-rifle-256-newton/Added More...
I didn't think nor wish to imply that the rifle in question was Newton built/mfg.
I thought the triggers were German and still do by their appearance of the ones used and recv'd by Newton from Germany on those contract rifles.