Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 148,143 pages of information and 233,681 images on early companies, their products and the people who designed and built them.
Claimed that in early 1850s he had produced propellors which predated the invention of Robert Griffiths; and that John Bourne and Co fitted propellors to several of their steamers built at Greenock; and that the first propeller fitted to The City of Glasgow, built by Tod and McGregor, was identical in principle to that patented by Mr. Griffiths.
1858 of Hartlepool Ironworks
1871 Designed the engines of the S.S. Evora, which were constructed by Thomas Richardson and Sons, of Hartlepool, 'from the designs of Mr. George W. Jaffrey, who is now the manager of Messrs. Tod and McGregor's Works, at Partick, Glasgow.' Cylinders 48" bore, 3 ft 6" stroke. 
Obituary 1905 
. . . engineer and shipbuilder, who was in his eighty-fifth year . . . apprenticeship as shipbuilder with the once renowned, but now defunct, firm of Thomas Wingate and Co, . . became manager to the old firm of Tod and McGregor, which founded the works now occupied by David and William Henderson and Co. at Partick, and built the first private graving dock in Scotland . . . .
Extra info on George W. Jaffrey:
Engines designed by G. W. Jaffrey are described and illustrated (lithograph side and top views). 
The Duncan Hoyle Paddle Steamer, in which these engines are fitted, was built by Messrs. John Scott and Sons, of Greenock, a firm as well and favourably know in connection with the past history and modern practice of naval architecture, as is that of Messrs. Scott, Sinclair, & Co., with marine engineering. This vessel measures 200 tons, her length is 145 feet, breadth 18 feet, depth 9 feet; and her engines, to which we are now directing attention, are of 90 nominal horese power. The two steam cylinders are each 37 inches diameter and 3 feet stroke, placed diagonally fore and aft the ship, and nearly at right angles to each other-the amount of divergence from the true right angle being a trifling extent due to the local necessities of the hull. They occupy a space on the vessel's floor of 15 feet fore and aft, by 5 feet 6 inches transversely.
We have ourselves a strong feeling in favour of the oscillating engine for most marine and river purposes; but we admit the existence of some force, in what the designer - Mr. G. W. Jaffrey - of the Duncan Hoyle's engines urges on behalf of this fixed-cylinder, direct-action arrangement. He claims an especial feature of superiority, on the ground that the weight is better distributed, covering a large surface of the vessel's bottom; whilst all the parts are firmly and rigidly bound together, so that no one part can yield from another. For this latter reason, the loose-working jingling action, not uncommon in old oscillators, can never arise in the engines now before us. They are obviously applicable either for direct connection with paddles, or as geared screw engines. The Duncan Hoyle was built for the Australian coasting trade, to run between Melbourne, Geelong, and Launceston. Her owner, Captain Kincaid, gives a most favourable account of her performances since she left this country; and particularly as a sea-boat, as she went out under canvas only. Besides this, later accounts tell us that her engines have worked admirably, and have not been afflicted with a single hot bearing, although put to work at once, just as they left the Scottish shores. Indeed, we have the best possible proof of her good qualities, in the fact that she has since changed hands as an advance of P10,000 upon her original cost.
George W. Jaffrey is mentioned in one other publication: Expansion gear of the engines of the Colombian constructed by Messrs T. Richardson and Sons, engineers, Hartlepool, from the designs of Mr. George W. Jaffrey. Engineering, 5, l7 April 1868 p.359, supplement.