Update!
So After a few shots of the Leverlution loads this spring at the range, I sent it SSK for a fishgill break. Much more enjoyable to shoot with a break (also fun to pull out at the range next to some yahoo blasting off with an AR and no brass catcher). Barrel length is a bit over 13" with ~ 1.5" of break.
I spent some time playing with the Hornady 300 gn bullets (#4500) and was really worried when the best 100 yard groups were ~ 6" or so. Last weekend I headed out to the range with a bunch of the Barnes 300 gn 458 SOCOM bullets over RL 7 and found that 43 and 44 gn loads resulted in nice ~1.5" groups at 100 yards with velocities of ~1800fps (other powder loads opened up to 6-8"). I think that will make an excellent hunting load for this fall.

Some of the other interesting things I learned are that the throat in most factory 45-70s is nearly non-existent. If I ever get to the point where I need (I guess want might be a better word) to get more out of the gun, I could lengthen the throat by 0.25 inches to increase the powder capacity and get an extra ~100+ fps according to Quickload. From what I have read and been told by JD at SSK, many of the factory chambers won't allow for the use of 500 grain bullets (Hornady bullets) due to lack of throat. Unfortunately the SSK chamber only lengthens the throat by 0.060 or I would have had them do it. Now that I've seen that the gun will shoot, I'm looking for a spring kit and some of the other suggestions that have been posted recently to tune up an encore.