re: Lodge cast iron, anybody cook with it?

So I have done a few pieces, some with the Easy Off method and some on the self cleaning oven cycle. Then vinegar to remove rust. I seasoned these with Crisco, and they turned out good after 5-6 rounds of seasoning. Cooked bacon in them, and I keep them maintained with light Crisco seasoning and also bacon butter (solidified grease). I screwed up the season on a BSR because I put it on a commercial gas grill to sear some dry aged steaks, and I think it got too hot.

The one piece that is giving me headaches is a No. 7 BSR that belongs to one of my wife's friends. I have honestly never seen a skillet in such a state of disrepair. When it was delivered to me it had so much carbon buildup in the bottom that I wondered what had been cooked in it. The buildup was flaking and appeared to be taking iron off with it, but it was hard to tell. I've used the Easy Off method twice on this thing and it still is about three different shades of black, as well as a healthy level of rust.

Wondering if I should try the self cleaning oven method as a last resort or take it to a guy who refinishes iron about 30 miles from here and have him look at it.. At what point is cast iron non recoverable?