The 76/7600 series has 3 lugs...the 760 is the one with 9. From the 760 on up they all used basically the same trigger group, but I agree, some felt better than others. It is not hard to do a trigger job on these rifles.
They were all "long" length actions, even though many were chambered in what is generally regarded as short action cartridges. Nice thing about that is that you can seat your bullet out to touch the lands {if that is the best for accuracy in your rifle} and not have a magazine length issue.
They are pretty accurate rifles, many will rival the accuracy of a bolt gun. The Model Six was the fancy one, it had high grade wood, a better polish and blue and a monte carlo cheek piece. It also had a neat "flare" around the forend. The buttstocks are the same configuration and will interchange with the 20 gauge 870.
I recently built a 760 in 260 caliber with a Shilen barrel and Model Six stocks.