if you can find a automotive machine shop with an oakite(sp) tank, take it to them. an over night soak
and the thing will come out virgin iron, just be there when they pull it and either have them steam clean it, or offer
do do it yourself just as soon as it come out. anything that is left on the casting that didnt come right off will be softened to
the point that pressure washing will remove it if you get after it before it dries again.
another alternative used by those in the machine tool rebuilders corner, is to put the casting in a barrel with a tight fitting lid, and spash it good with laquer thinner, and then seal the lid down and leave it for a day or two, the fumes will attack and lift most all types of paint. seems to work very well for those guys, i can't imagine the indians using some kind of epoxy paint that wouldnt be affected by laquer thinner.
oh yes,,, and they too complain about finding fillers use to smooth out their castings as well.
bob g