A quick post-script -
I found that Freeport outlet centre near Braintree have both Samsonite and Antler stores. I got a couple of Samsonites (not current models but still quite big & quite good) on "buy one get one half-price".
I did notice that at least one shop gave discounts on production of a Stansted ID card. I don't think it was a luggage shop but since I don't work there I didn't pay too much attention.
Also, a big thumbs-up to Carlton Luggage - the wheel on my battered Airtec gave up after 12yrs or so. They sent me a new pair FOC.
ap