Dennis: When I checked Frances Coakley's "A Manx Notebook" (see link above), for biscuit factory, I came up with the following:

R. D. Cowin, Bread and Biscuit Baker, 2, 35, and 38 Prospect Hill, Douglas.
-This superior business was founded in 1871 by the present proprietor. Such has been his energy and enterprise that twenty years he has added two large branch establishments. This success is owing to the superior quality of his goods, and the untiring energy; displayed on all occasions. He has spared no expense in procuring any appliance necessary for the rapid execution of orders, or of improved machinery. The consequence is that the bakery departments are as perfect as it is possible to make them. The specialities turned out are in biscuits: lunch, cracknel, water, Mona, cream, Albert, Abernethy, cabin ,&c. ; and in cakes: sultana, Queen, plum, seed, rice, sponge, shortbread buns, &c., &c. These are all of exquisite flavour, and composed of the very best ingredients. The patentee has granted to Mr. Cowin the sole right to manufacture the patent Extract of Malt Bread, biscuits, and rusks, for Douglas. These wholesome and superior delicacies are the patents of Mr. Montgomerie, which were awarded the Gold Medal at the Industrial Exhibition, Glasgow, 1886-1887, and the highest award Prize Medal at the International Exhibition, Edinburgh, 1886. The three shops occupied are all extensive, and admirably fitted and furnished. The principal one, 38, Prospect Hill, is a substantial building of three-storey elevation, with a frontage of twenty-four feet, and depth of ninety feet, A large and competent staff of assistants is employed, especially in the season, and everything is done that is possible to study the convenience of both residents and non-residents. Mr. Cowin is very highly respected in the town, and in the districts surrounding it. He is an enthusiastic Freemason, and holds office in the Spencer Walpole Lodge, no, 2,197, Douglas. -

Hope this helps.
Pat