And is this story of Brinley Edmunds who died in WW1 and whose father was an engine driver related? If so there is another item belonging to the family held in the museum
museum.wales/blog/915/Bri...

By 1926 the Barry Railway was part of the GWR, the town had grown enormously and the great coal trade in south Wales had already peaked. How many of these millions of tons of coal did Driver Edmunds haul in his locomotives? It can now be seen at St Fagans in Rhy-dy-car cottage 5.

Could it be that the second journey originated in Wales and the fare cap is an English not UK thing?

I noticed them today too. Still showing timetable times rather than actual, so no more useful. I find Bustimes.org handy as it shows the progress of all the buses and not just the Cardiff bus ones.