Thanks Peacoat I also thought it was the real deal but just wasnt sure with the feel of the material.
When I said 'taught' I mean I buttoned it and lifted the sleeves to get right under the pit and measured it likeso. Hence whilst it was held 'taught' but not overly tight. I'd say it would be a 18 had I laid it down and measured it without disturbing the fabric. I will take more detailed measurements later on and post them up. Any particular measurements you want?