I still think that such info should not be hidden from the buyer if asked. Me as a buyer would like to know more than just " Made in England" knowing that Purdey is not a shoe manufacturer ..
Not all are shoe experts to tell if the boots really worth the value and knowing who makes them might help with the decision and piece of mind. Of course, no one is forcing me to make a purchase ..
Take a look at this example: W.R company in UK they clearly stated in description Edward Green made the pair for them..
The example you gave is much more analogous to PCK1's Ben Silver example above. Westley Richards is selling EG shoes, just as Skoak or Edwards of Manchester sells EG shoes. They're not selling (at least not on this product) a private label. It's a non-standard color but retailers frequently have exclusives.
Again, I don't see what the big deal is. It's not like they're hiding some big secret. Do you think RL should disclose which factory in Pakistan makes their shirts?
It all comes down to whether a retailer feels that they can maximize sales using their brand or using somebody else's brand. RL, BB and Purdey clearly feel that their brand is more recognizable and/or more in line with the brand identity they want to project than C&J, hence the RL/Peal/Purdey branding on the products. When J Crew markets shoes as being made by Alden or Alfred Sargent it's not because they're being more honest, it's because they feel that those two names have greater brand equity than their own and kick the offering upscale a notch.