Yeah, but the difference is that the Kettle you are using indicates a spangen construction which fell out of popularity by the end of the 13th century in most places of Europe. The reference you are looking at, is not spangen construction. It has rivets to the side to hold up the lining within the Kettle, as well as a ridge formed on the top. The kettle you have has rivets to keep multiple pieces of plates riveted in frame. Which only makes a lot of sense in a time when fires in forges couldn't be hot enough to beat the impurities out of objects which would break if made too large. Also, I would stay away from Osprey illustrations, and instead reference from the original art pieces and artifacts the Osprey Illustrator speculates from.