Do I assume your grandparents to be Edwin Orcheston Findlay (b1889 at Poplar London) and Daisy Esther Louise Gardner (b1887 Hackney London)?
Do you have any dates or places that they were in/returned from India and Singapore?
I have a contact who lived in Ceylon who seems to remember the name of Findlay and Son who she thinks were probably agents. Her husband lived in Singapore but doesn't remember the name at all. There again, why should he/