I had trouble with a cotter the other day that I pressed half-way out and would not BUDGE any further after moving the 3/16" to where the threaded part was flush with the crank. It was one of the really worn cotters that would allow the crank to move an inch or more at the pedal without the spindle moving. I must have wedged a bit of worn metal sliver in somewhere.

It was on the non-drive side so I was able to pull it off the BB and work on it in a vise. Your issue looks like it was a PITA. I've since modified my press to accept a special longer pin that will press further into the recess in case this happens again. Here I was showing my press off to someone and attempting to look like super-wrench when the darn thing failed me. This was the most difficult cottered crank I've ever come up against -including the ones before I got a press.

I like your solution. Wood is real!