Correspondence arranged in alphabetical order, as set out below. The number of items is given in brackets.
- Boulton & Watt, of Soho, Birmingham, Warw (1)
- Buchanan, Robertson, of Rothesay, Scotland (1)
- Burns & Coats, of Paisley, Scotland (1)
- Campbell & McLean, of Paisley, Scotland (5)
- Clarke, Benjamin, & Son, of Dublin, Ireland (1)
- Dearns, Andrew, of Paisley, Scotland (1)
- Fallows, John, & Co., of Warrington, Lancs (1)
- Fishwick, Robert, of Whittle, Lancs (2)
- Hamilton, Hill, of Belfast, Ireland (9)
- Handyside, James, of Glasgow, Scotland (6)
- Hannay, George, of Bangor, Ireland (8)
- Heywood Brothers, of Manchester, Lancs (1)
- Johnson, Alexander, of Belfast, Ireland (2)
- Kennedy, Robert, of Glasgow, Scotland (21)
- McBurney & Thompson, Newtownards, Ireland (2)
- M'Culloch, Alexander, & Co., of Bangor, Ireland (2)
- Orr, Robert & Company, of Paisley, Scotland (3)
- Salvin Brothers, of Durham (1)
- Templeton Jamieson, & Co., of Glasgow, Scotland (1)
- Wright, Thomas & Richard, of Belfast, Ireland (1)