For some reason 79 is not displaying a route number but it must be working on the 172 as Rhondda's Buses other route to Porthcawl (from Pontypridd) only ran on Sundays, and infrequently at that.
Behind is a former Maidstone & District Willowbrook-bodied Leyland Leopard VKN 835X working for Porthcawl Omnibus.
From an original slide in the David Beilby collection, photographer unknown