Hi LD a possibility ??
Coflein
http://map.coflein.gov.uk/ describes a house called Mill House which is a former corn mill now converted into residential property, possibly on the site of a medieval corn mill. Historic features of the mill removed with conversion and extension, now presenting an aspect of a two storey house, externally rendered and painted with a slate roof. Central porch of 20th century date on front elevation, above and to the left of which are segmental arch-headed windows with pronounced brick dressings containing replacement casement windows. To the right of the porch, on the ground and first floor are double segmental arch-headed windows. Gable end chimney stacks of brick.
You can see it on Google maps if you search using the words 'Magor Motors'
Adjacent to the house are a range of mid and late 20th century, prefabricated, light industrial buildings of concrete, aluminium sheeting or plyboard construction, the whole forming sale areas and workshops for Magor Motors.
