Thanks everyone for the advice.
Back axle now off and half the spring pin now sawn off but now need a new blade!
Previously tried very heavy hammer and drift lots of very hot heat, twisting the spring pin, hitting it in both directions and swearing profusely.

Location: Devon

Nick,

If you can take the hub off, then you can hit both ends of the spring pin.

This will loosen the grip on the cotter.

hopefully you haven't bent the thread over to much, it makes it a bit harder to remove.

Tony

Location: Leics

Sevens abound with cotters, few of which normally exit easily. As I have suggested before, those with lathes can make a cotter from a piece of tough stuff in the time it takes to order. It may not look pretty but if the full end is extended and tapped can pull out with a nut. May not be space for in all cases.

Bob Culver

Location: Auckland