Following the Finance (1909-1910) Act of 1910, registers of duties on land values were compiled, forming a complete record of land ownership and property values in the period c1910-12. The registers, also known as Domesday Book, were accompanied by a corresponding series of 25":1 mile Ordnance Survey maps.
The links below lead to PDF documents.
Welshpool valuation district (46 vols.) (Ref: M/LVR)
Welshpool valuation district (31 vols.) (Ref: R/LVR)