cprher: Even if you don't want to strip it, at least confirm that there is proper upward force at the tip of the forend. I've had a couple of virtually new looking No. 4's that did not. Cosmolene or not, these are old rifles (and if it's painted, it can't be mint) and I would suggest you learn the drill and strip before shooting. You can easily learn what to look for perusing the material in this forum. As to accuracy, my own well used Longbranch easily does 2-2.5inch groups (at 100 yards). Have fun with it.
Ridolpho