CSS183U used to be perm 980 S102 shift, whereas TIB658K was doing
full day. That was in May when AMDEP took 2 more full day duties
from WLDEP, TIB934M and TIB939A became perm whereas TIB658K and
TIB673R was out. TIB658K remained WLDEP SP for a while and went
back to service 980 under S102 shift replacing CSS183U (perhaps
could be due to the ad), somewhere in June.
so now, what are the 3 permers?
the full day bus is 665P?