Is the green one ex Megabus / Stagecoach Kenya? They had the extra window vents I seem to remember. Great fun as the Manchester student bus.
I guess the NI reg is a personalised plate?
Nope, it's an ex Hong Kong Leyland Olympian like cms206's Jolly Green Giants, imported by Brightbus of Sheffield. The Stagecoach Kenya buses were Hong Kong-style Dennis Dragons with Duple Metsec bodies assembled from CKD kits by AVA in Mombasa. Those full-depth opening windows were pretty standard on buses without air con in hot countries. The NI reg is a personal plate - the same operator also has TIL 6572 and TIL 6573.