Just saw some LO3x on 21, 22, 25, 55, 72, 97 and 54 recently. Even saw 1 cameo ( i think) on svc 30 when it was about to enter the expressway.
Looks like they are scattered all over various services where each service has a few of these LOs.
service 90,157,most of the JIS service and most of the toa payoh, bishan DDs service