My gut feeling is that if 28G - 31X did not appear in Yishun
rosters, it might be somewhere else... Sembawang? Haha...
They could be reserved for any of the services that comes under
AMDEP already, or perhaps still SP running around.
If they really appears in Sembawang, I hope that service 980 is
the one getting them, those Nissan UDs ought to be replaced.
Or could it be on service 67 getting more OC500LEs instead? Or
maybe service 854 getting more of them for the next few weeks
(based on the running sequence).
Btw info from SBS877M is that SMB34M - SMB38C is confirmed under
AMDEP.