"Techniques of Medieval Armour Reproduction" by Brian R. Price. Covers armour construction from the 14th century. He includes some modern techniques, but also goes into historical methods as well.
"Cathedral, Forge, and Waterwheel" is a nice book, but I'd approach it with caution. I read it and discussed it with my old college advisor, who's a medieval historian. I had found several mistakes in regards to the arms and armour of the middle ages, and we both agreed that while it's a fairly good introduction, the material is a bit suspect.
Cheers,
Nick