I suspect Old George was father of the George Booth I blogged about previously here, as this portrait (by an unknown artist) also hangs in Dunham Massey, now in the hands of the National Trust. Old George wears some kind of unidentifiable wrap over a linen shirt with an attached collar and decorative tassels on his bandstrings. He also has a black cap with lace edge, which could be part of a liner that could be removed for cleaning. There is an example of one of these in the collection of the Museum of London.
Old Sir George Booth