"Finney stars as a Dublin bus conductor who is addicted to Oscar Wilde. He entertains his passengers with declamation of Wilde's verse. The film features a number of preserved CIE buses
of the period including a Leyland Titan and a number of saloons including an ex GNR Gardner." (thanks Chris Hough) I can't confirm the GNR, but CIE buses appear throughout the film, often in the background. However, definitely seen are:
CIE R788 (OIK984), a 1958 CIE-bodied Leyland Titan OPD2/2 - this is the bus used for interior filming:
CIE RA73 (OYI838), a 1959 CIE-bodied Leyland Titan PD3/2:
CIE P347 (ZO6857), a 1953 CIE-bodied Leyland Tiger PS2/14:
I believe this is CIE P220 (ZJ5960), a 1951 CIE-bodied Leyland Tiger OPS3/1, but would welcome confirmation:
R788 is the star of the show, in one scene being used to run a car off the road, and Finney is great!