Here's a list of businesses (and their ratings) in the Manufacturers/packers category.
In England, Wales and Northern Ireland food hygiene ratings are provided by the The Food Hygiene Rating Scheme (FHRS). Ratings in Scotland are provided by a similar scheme called the Food Hygiene Information Scheme (FHIS).
You can read more about FHRS and FHIS food ratings here.
Click on a establishment below for more information:

Total Score: (lower is better)
Unit 6, 88 Mile End Road, London, E1 4UN

Total Score: 20 (lower is better)
10 Hackney Road, London, E2 7NS

Total Score: (lower is better)
Bakery 4 Limited Unit A.1, 76 Smeed Road, London, E3 2NR

Total Score: 0 (lower is better)
PERFECT HYGIENE RATING SCORE
48 Lanterns Way, London, E14 9JP

Total Score: 5 (lower is better)