SBS9449G
(AMDEP 59), SBS7724A
(AMDEP 55)
SMB8008L
(AMDEP 812),
TIB1218R
(AMDEP
806?/SP?)
SMB8009J
(AMDEP 851),
TIB976S
(AMDEP
800?/SP?)
SMB8010D
(AMDEP 854),
Replacement unknown
There was a swap involving 976S (ex-AM 800),
1020T (ex-AM 854),
1060C (ex-800 then SP) &
1092K (ex-AM 804 then SP) not too long ago. It's
probably linked to where 976S & 1218R's statuses now. I suggest
you go and find out more from the people who stay in
Yishun. 
I do think 976S & 1218R are SP for this month though till
June Sch Hols are over.
Anyway, 9449G & 7724A's swap is confirmed
with perm stixs? or observation? I know i've seen both buses
frequently too on the abovementioned svcs, just wondering if
there's any new perm stixs for them?