I don't think burning in the sky would work as the negative (upon inspection on light table) is absolute pitch black with no trace of details whatsoever... and farmer reducer which I never used but common sense tells me that it would not bring detail back where it doesnt exist in the first place... but since I never used it, is it possible that I might start seeing detail where I could not see it now ? just wondering.
Now, I dont know what lith-paper is and what it does, so I will research this to find out what is it about.