Info by various bus fans:
Not so rare:
SBS 0159 C 021 (AM SP)
SBS 0171 R 076 (AM SP)
SBS 0193 C 241 (SL 098)
SBS 0256 E 030 (SL SP)
SBS 0277 U 133 (AM SP)
SBS 0329 D 030 (SL 157)
SBS 0488 C 199 (SL 243)
SBS 0599 R 069 (BN 038) - experm
SBS 0932 L 154 (SL SP)
SBS 1912 M 183 (SL SP)
SBS 2598 E 078 (SL SP)
SBS 2788 Z 078 (SL SP)
SBS 2791 M 069 (BN SP)
SBS 2833 B 069 (BN SP)
SBS 3840 Z 030 (SL 097)
SBS 3849 A 058 (AM 135)
SBS 8042 C 502 (SL 154)
SBS 8232 X 038 (BN 069) - replace 8422P
SBS 9133 S 058 (AM SP) - replace 9035S
SBS 9547 G 098 (SL SP)
SBS 9813 M 010 (BN 222)
SBS 9819 Y 010 (BN 069)
SBS 9849 K 030 (BN 069)
More interesting ones:
SBS 0118 X 021 (AM SP)
SBS 0896 H 097 (SL SP)
SBS 2994 U 143 (SL
105)
SBS 7371 J 143 (ex-BB SP)
SBS 7451 L 143 (ex-BB SP) back to slbp
SBS 8020 R 098 (SL 078)
SBS 8395 J 228 (BN SP)
SBS 9168 S 030 (SL 182)
SBS 9378 C 154 (AM 055)
SBS 9630 Z 055 (AM 070)