I am trying to find a source of tiny woodscrews. Making dolls house stuff, and trying to find a supplier of about 50 countersunk brass woodscrews 1/4 inch #1. These are about 1.2mm in diameter. Currently I am using 10Ba screws, but not the best for holding in wood.
Try "Hobbies" (www.alwayshobbies.com) or "Hobby's" (www.hobby.uk.com) – both companies have them in their paper catalogues. Hobbycraft might also have then as they do fittingds for dolls' houses.