Very interesting, but could I ask please the following questions:
* The 77 route - was it heavily patronised, especially during the Summer period?
The '77' was worked by Swansea (Brunswick) depot, which had around 100 buses 'on shed' at that time.
The route was essentially a cross-city operation which linked Pontlasse (nowadays the vast Morriston Hospital) in the northern suburbs, via the City Centre and the sweep of Swansea Bay with Mumbles Pier and Limeslade. End-to-end scheduled running time was around an hour, and it ran to a basic half-hourly frequency along it's entirety, with half-hourly 'short workings' dovetailed-in between the City Centre and Mumbles Pier.
The first bus of the day left Brunswick at an unearthly 0325 hours on Mons - Sats; whilst the last returning bus ran-in just after midnight each day.
These heavily-patronised routes were 'all stops' along their entire length, so obviously the Regent Vs took a constant hammering, seven days a week.
There were also the 74/75/76 routes which followed the 77 as far as Oystermouth, before branching-off to Caswell Bay/Langland Bay/Newton. So, looking at the timetable you'll see a bus every few minutes along the Mumbles road.
In addition to these there were the 84/85's which served the same destinations on a half-hourly frequency, though these left Swansea via the leafy western suburb of Sketty.
The Summer timetable saw these frequencies increased further, and brought about significant challenges to the Company, especially when the sunny sunshine turned to rain in the afternoons.
Droves of folk would suddenly dash off the beaches and require immediate homeward transportation. As experienced operators, SWT seasonally based an Inspector at Oystermouth along with a few spare Regent Vs and crews, ready to move the masses as the need arose.
Willowbrook-bodied 586:

... filmed in action on the '77':
http://www.youtube.com/watch?v=82nHBeq3jkMListen to the melodious D166 'box! Any more questions ... on the Regent V?