"...should be 20 teeth..."

have you tried using the standard 20t tool yet?
and i've not been impressed with the longevity of "sealed" BB's so far... most last about 1/4 the time of a good quality "loose ball" BB... my shimano 600 BB had about 20K miles on it before i needed to replace the balls and spindle... mostly because i didn't change grease for the last 5K or so... it has SEALS in the cups... the tiny bearings in those internal, more heavily loaded, bearings are the wrong type of "seals", and the nature of that design places higher loads on the bearings due to their farther in location on the spindle....... they're called "Dust Covers" in similar "sealed" bearings, btw... and most "sealed" bearings are sold with little to no grease in them.... i always popped the seals out and repacked them before install in various ag. equipment applications.... not an option with the internal BB's i've seen...