BrianJ,
You are correct,the Rem Int'l is single stage.
I haven't used mine in years.
Some people collect cartridges,I collect trigger groups.
Fred J,
Remington Int'l trigger group adj screws fwd,middle,aft are as follows;
Forward screw-sear engagement
middle screw-trigger pull weight
aft screw-over travel adjustment
The OEM Remington International trigger group shoe attachment rail was machined from bar stock where as the Hart was a stronger cast/forged piece if memory serves me.