The problem with helmets ported from Medieval 2 Total War is that since they were made with the purpose of having hundreds of units on screen at a time, they are of very low quality... If you do find them keep in mind they will be low-poly and have low-res textures.
Perhaps.... I just thought I saw one similar to the one the thread maker asked for so I posted a image of it. I don't know where the helmet was created, Mount doom perhaps. All that helmet would need is that straight cross symbol placed down the middle of the helmet and polished if you wanted it to be more silver and bright.