When I got Iron ships, I thought I might be able to build ironclad battleships, but when I went in and looked at the units, it said I was still only able to build wood screw battleships, so I passed.
However, later I decided to build one and imagine my surprise when although the unit displayed in the production screen was a wood screw battleship, the ship being built was an ironclad.
The same thing happens with scout squadrons. It says I'm building a wood screw corvette, but I am actually able to build an ironclad corvette.
Is there any way to get the picture in the production screen to update? I guess I can remember that it's really ironclads, but it's a bit frustrating for a new player.