Peter Egan accepted the part of Paul Ryman whilst in the United States, and so couldn't see a script before the series would be going into production. He asked who was in it, was told Richard Briers and Penelope Wilton, and took the offer immediately.
Paul's habitual wry amusement whilst speaking with Martin was entirely due to the fact that Egan found Briers a hugely entertaining person in reality; consequently the smiles were genuine and he cleverly used them as part of his characterisation.
Ann Davies suggested Peter Egan to be cast, aware of how well he and her husband Richard Briers had got on together in the BBC's production of George Bernard Shaw's Arms and the Man (1983). Davies played Martin's Mole Valley Valves secretary Mrs Ripper in the final two episodes of the series.
Richard Briers preferred this series to The Good Life (1975), having more sympathy with put-upon but well-meaning Martin Bryce than the perhaps selfish Tom Good.