I think this may have been the same place my grandmother worked at sometime before 1923. I thought it was a private house then and I believe she was a ladies maid. I can remember seeing red brick walls which looked a bit like a walled garden when she showed it to me around ?1970. I don't remember seeing the house as such. I googled Minsterworth and just after Oakle Street went into street view, then clicked photos. The first picture that comes up is of the Severn bore, but in the background are red brick walls and an archway. I think this is the same place. If you do find out any more I would be interested!
This could be the same place as Duni House. See the following description www.victoriacountyhistory.ac.uk/.../Minsterworth