In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Treuddyn like this:
TREDDYN, or Tryddyn, a chapelry in Mold parish, Flint; 4 miles S by E of Mold r. station. It has a post-office under Mold. Real property, £11,156; of which £7,200 are in mines. Pop., 1,525. Coed-Talwn collieries and iron-works are here, and have a branch railway for minerals to Padeswood r. station. The living is a p. curacy in the diocese of St. Asaph. Value, £140.* Patron, the Bishop of St. A.
GB Historical GIS / University of Portsmouth, History of Treuddyn in Flintshire | Map and description, A Vision of Britain through Time.
Date accessed: 25th March 2017
Click here for more detailed advice on finding places within A Vision of Britain through Time , and maybe some references to other places called " Treuddyn ".