SC276 would more than likely have been on the 240 to Ballycotton as it's the marked in bus on the route. I doubt it was SC278, that's outbased in Skibbereen for the 237, although it's usually on local runs while in the city, but normally it does a lap or two of the 245. The 240 serves Carrigtwohill.

Just to add to Colm's list (saw most of them myself funnily enough):

VWL170 would have been on the 1S as well if it was on the 8
VWL187 - 2D
VWL162 - 2W/2E
VWL157 - 3
MC18, VWL169, VWL190 - 4
MC19 was also on the 7, as was VWL185
DD12 - 9

VC321 - 418
SC246 - 419
SC20 - 424, extremely unusual
SC248 - 456

SP105 - X20
SP95 - 051 (both SPs still have the mega for the VW bank)
SC64 - 052 (in a shocking state, typical for a Ballina bus though)

SC232, SC282 - out of service in Ceannt Station