I know of a sugar-refiner in Greenock called Wrede, and I see you have several entries for that name on your database. Here's an extract from a little document I drew up for my own interest a year or two ago. The Rev. James Stewart was distantly related to my family -
"The Rev. James STEWART died in 1917 at the manse in Peterhead, and his death was registered by his “intimate friend” Frederick Lear WREDE of Bentinck Street, Greenock. In the 1901 Greenock census, Mr. F.L. WREDE is a “Steam-ship owner”. He was born in Greenock in 1850 to Lear WREDE, “Sugar-refiner”, and Janet SERVICE."
Harry