Tink i agree and confirm the 1st 2 for you...
the bus tt wen out for sv12 is prob 7337J
As far as i know and IIRC, 7337J has been on 12 the same days
that 7331A was on 12. Although yes 7331A has stuck to 12 for
weeks.
But if you consider the amount of WAB services BNDEP has, and
the number of B9 SPs they have (2 to be exact excluding the new
Wrights, ie. 7331A & 7338G), could it be possible that SBST is
following SMRT's previous tradition of SP buses still having
ads?
It's just my guess though, because the no. of WAB services in
BNDEP (2, 5, 12, 17, 19, 21, 30 etc) would mean that even if 7331A
is SP, there would be little or no possibility of it at all lazing
around in the depot any day? The exposure for the ad would just be
as much as being perm on any service. Just a thought though from
the logical point of view. 
