Starting from 'They would then take their body measurements to any of several participating retailers, who pass the information on to their apparel suppliers and have the clothing custom-made.', does it naturally lead to the conclusion 'The body measurements would be given to the participating retailers.'
They would then take their body measurements to any of several participating retailers, who pass the information on to their apparel suppliers and have the clothing custom-made.###The body measurements would be given to the participating retailers.