My 1982 Bentley has recently been restored (apart from the original ‘genuine leather’ upholstery). The seats have become stained and ‘scuffed’ over the years and a friend has suggested I clean and dye them with an Eastwood ‘spray’ dye. Can you recommend a ‘procedure’ for cleaning and preparing the leather prior to applying a spray dye. Can the ‘Pre Painting Prep’ product be used in this context? Your advice will be appreciated. Thanks and regards.