Stuck Chuck

I have a Jacobs 633C 33 Taper chuck on my drill press which I
inherited. I've noticed a significant wobble with all bits. I'm
thinking I need to remount the chuck because the arbor seems to have no
runout.

I found this great article:
http://owwm.com/files/PDF/FAQ/drill_press_tune-up.pdf that has helped
tremendously. My chuck has a collar above it which I'm supposed to
turn down to push off the chuck. I don't have a pin spanner so I used
a strap wrench to turn the collar. At first it didn't turn at all but
then it broke free and turned rather easily. I turned probably two or
three revolutions before meeting resistance again which is when the
collar began pushing the chuck. The instructions say that it should
meet resistance at this point. I continued trying to turn it with no
avail. "That's okay" I thought I'll just back the collar back up and
put some oil in there to help. But now the collar won't turn in the
other direction back up the arbor. I've saturated it in oil and WD40
with no luck. I've tried turning both ways so hard that I've also
slightly deformed the chuck holes where the key fits!

Any suggestions?
Would a spanner give me more leverage? What sort of stores carry them?
Would an auto-parts store carry them? Home Depot and Lowes sure don't.