I have two questions involving the evolution of plate armor when did small plate armor (brigandines, coat of plates ect) move from having just an augmentation to mail into an armor in thems self and second when did plate iron gauntlets come about meaning anything other than mail gloves/mittens

I think you can find gauntlets regularly in artwork from second quarter of the fourteenth century. Examples of scale construction can be found earlier though

By the last quarter of the 13th century we start getting references to militia using coats of plate instead of haubergeons. Those who could afford it wore both mail and coats of plate. Gauntlets of iron start being mentioned about the same time, but this could refer to separate mail mittens. I agree with Felix that most "plate" gauntlets don't start showing up until c.1325-1330.