Stuck adjustable cup, 1994 Chorus in AL shell

[oliver1850]

Lock ring came off with difficulty so I was anticipating a fight with the cup. Didn't want to break the pins off the cup tool (been there) so have been proceeding with caution. I was able to remove the drive side cup by clamping the wrench down with the crank arm bolt and a stack of washers - and hammering on the wrench with a 2 lb rubber hammer. Had to hammer it almost all the way out before I could turn it by hand. Plastic sleeve over the spindle was so stuck that I had to twist it inward with needle nose pliers while spraying penetrating oil in the gaps to remove it. Now have soaked the threads from both sides and rapped on the cup from both sides with a brass punch. Tried the rubber hammer on the pin wrench but didn't get too aggressive - I don't think the cup moved.

Is there another option for a tool? I think a left hand threaded bolt and nut, somewhat smaller in diameter than the spindle, appropriately sized bushings, and an impact wrench would work. A long enough right hand thread bolt with the impact wrench on the right hand side would do the same job and be easier to source. That will probably be my next attempt unless someone has a better idea.