Yeah we'll need pic of the dropout and perhaps the derailleur hanger next too it... when you say raised bit it makes me thing you have a dropout that is either forged (which would most likely have an integrated hanger) or one of those old simplex stamped drop-outs that have another plate brazed to them for extra strength (at least that is how I think they are constructed. I could see a problem of the bolt which hold the hanged in the dropout being a little to short if the DO is too thick but then you could just use a longer bolt.