Addis - A surname that turns up in Radnorshire as early as 1634 and which was found mainly in Bugeildy parish well into the 19C. The name is said to derive from a pet form of Adam and occurs most commonly in Herefordshire, Shropshire and Gloucestershire, see here. Ade also occurs as a Welsh patronym - the Werdutvil daughter of Ade of Bleddfa in the tax assessment of 1293 and a local princeling Meurig ab Ade, fined 100 marks for rebelling against King John in 1211, are examples. It could be that the Radnorshire families owe their origin to this forename and their name is as patronymical as their Price and Cadwallader neighbours.
Minton - The surname can be found in the 1670 Hearth Tax for Colva and was there as early as the 1650s. Researchers might miss it though since it is omitted from the index to the tax published in the 1991 Radnorshire Society Transactions. The family may have originally come from Minton in Shropshire, although by 1688 John Minton was happy enough to see his daughter christened Gwenllian in Colva parish church. There were still Mintons in Glascwm, Rhiwlen and Bryngwyn in the 19C although others had migrated to the coalfield. I'm not claiming any Radnorian connection with this "date from hell" mind.
Wozencroft - Can there be a local surname with more spelling variations: Woozencroft, Worsencroft, Wosencraft, Wostencraft, Wostencroft, Wozencraft are just some from the 1841 Census. It's a name that was found in the Radnorshire parishes of Bugeildy, Llanbister and Llanyre in the 1670 Hearth Tax, having come into the county from Montgomeryshire where it crops up in Llanidloes as early as 1578. Said to originate from the Lancashire placename Wolstencroft it no doubt entered Wales as part of the Elizabethan plantation in Western Montgomeryshire. The 19C censuses show that Wozencroft and Wozencraft are overwhelmingly names associated with Mid Wales, see here for example. Who knows, perhaps the family of the author of the book on which this cult movie is based - it's available to view on youtube - came from Radnorshire.