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...on the cotter thing, often it turns out that if they stick badly, it is on only one side. If that is the case, see if you can get the remaining crank parts off by pulling the cup on that side (italian cups so both RH). This makes it so much easier to work on, especially if you have to drill it out.
I've had some luck with Freeze Off, but read here recently that a mix of acetone and ATF has better penetration. Also, of course, the torch business, if you are so inclined, seems to work.
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