For old maps http://www.lancashire.gov.uk/ Maps and related information online. Use post code (LA3 3HD for the centre of Overton). The OS First edition 1:10,560 mapping for Lancashire was one of the first surveys undertaken by the Ordnance Survey. The original maps were surveyed in the mid1840s and published in the late 1840s. A revised version was also produced in the 1860s. 

1930's map of Overton and a diagram of the Ship Hotel and Pedder Farm from 'A Farming Year in the 1930's' by Edward Baxter.