In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Blaenpennal like this:
BLAENPENAL, or Llanpenal, a chapelry in Llanddewy-Brefi parish, Cardigan; on the river Aeron, 4 miles NW of Tregaron r. station, and 26 SW of Llanidloes. Post Town, Tregaron, under Carmarthen. Acres, 4,105. Real property, £1,115. Pop., 522. Houses, 107. The property is much subdivided. The living is a p. curacy in the diocese of St. David's. Value, £84. Patrons, the Earl of Lisburne and R. Price, Esq. The church is good.
GB Historical GIS / University of Portsmouth, History of Blaenpennal, in Ceredigion and Cardiganshire | Map and description, A Vision of Britain through Time.
Date accessed: 23rd 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 " Blaenpennal ".