This from a 1901 newspaper obit - the Welsh newspaper site sems to be having some techie issues so I can only grab this excerpt from the search results
..daughter of Rees Jones, of Brith- waenydd Farm, and the young couple lived in Bridge street next door to the saddler's shop. It was here that the Rev Rees Morgan was born. His parents afterwards removed to what is still known as the Old Harp,on the Cardiff-road, an old house nestling by the rubbish tips created by the Dyffryn Blast Furnaces, where the father continued his labours as schoolmaster
Also, from 1910
Troedyrhiw Building Club propose building 34 houses on the west side of the main road, near the Old Harp, at Troedyrhiw