Re: Any tips for removing corroded bolts at rudder?
Hard to tell from pics but... How about a thin reciprocating saw blade between the "yoke" and the stub? Cut through the bolts and then drive them out when you withdraw the stub. It might sacrifice the surfaces between the two pieces a little but that can be fixed after they are apart. I have a small battery powered recip saw that has helped me through some difficult "blind" problems.
Islander-28, Marshall Sandpiper