while the action soaks in penetrating oil - I started scrubbing the stock with Murphys oil and a blue dish scrubby. the grime is coming off...very slowly. You can't even see wood on the parts I haven't scrubbed.
the pile of corrosion on the barrel ended up being a combination of rust and swollen wood fibers. actual metal is seems easily pitted but serviceable. the pile of corrosion was a huge bubble several mm's high and I was worried the barrel was corroded too deep to salvage. penetrating oil overnight dissolved all of it.
I'll take pics over the weekend.