Luke45, the best thing you can do is clean it the way you usually do, then take it to a local smith with an endoscope to inspect the chamber, throat and the entire bore. If you have the chatter marks, just get rid of it and put a decent one on. Be aware of the "carbon ring" issue too, although that would degrade accuracy over time, not be a constant from day 1.

When considering a rifle as a donor, I always try to find all the features I am looking for in the stock/action/magazine/receiver/trigger first. Trying to fix any of those individual or cumulative issues after buying a "cheap" bargain basement rifle is usually a LOT more time consuming and expensive. Given the way it is basically impossible to find Savage factory parts in stock anywhere for the last 4 months or so, I think you will get what you wanted the fastest way by just changing out the questionable part which is the barrel. When I do a build, I usually start with a model 12 in stainless or a 112/114/116/110 (the 112-116 are uaually stainless). I also pay attention to the way the magazine is configured. Right now it is really hard to find parts anywhere to re-configure a magazine and the parts are not cheap if you can find them either.

All of the other parts on your rifle should be decent. If you can find a way to replace the "bottom plastic and magazine" on your 111 with a "real" bottom metal and steel mag, then do that too. (If I recall the 6.5x284 LRH is a model 111 ?) Unless I am mistaken yours has the accustock, which you might tweak with a bedding job, but it should be a considerable improvement from the stock on a "package" rifle, stevens or axis. I doubt very much that you will find contact between the barrel and stock on your rifle, but the bedding is probably not perfect.