Well I guess i'm going to have to caveat what Ian said with a couple of things. who do you want to be? The gear worn by the guy in charge will not be the gear worn by the guy working for him, often the guy working for him will be wearing gear that is older. Less money = less or older gear. Example the battle of Wisby fought in 1361 on the island of Gotland. Rebellious peasants vs the upper crust. The peasants came out on the short end, thier the majority occupants of the grave pits. Thier gear is widely acknowledged to have been 10-15 years out of date at the time of the battle, COPS over mail, many plate gloves riveted to leather and sewn to a base leather glove with cuff constructed from splints, widely simply refered to as " Wisby gauntlets " today ( which can also be found in some German and a few English funnery effigies from the 1340's ) but the folks with less money were still using it. This is a historical truism, money influences what you had to use. Additionally armour was expensive and therefor not simply chucked out because it was not " of the latest fashion " it was passed on. There are a number of " wills " if you will, lists of how the belongings of upper class folks, the nobility if you will were disperesed that show armour being given to retainers and loyal servants. The concept that you have to " nail it donw to a decade " is flawed unless you first decide who you want to be, if you want to be top of the food chain guy, that means something very different than man at arms/retainer guy, and a German top of the food chain guy c 1340 ( where head to toe mail, with minimal plate beyond head gear was only just becomming unfashionable ) will not be the same as top of the food chain French guy ( distict differences between northern and southern French fashion for example ).
As far a splinted stuff goes, it appears in funnery effigies/artwork mid 14th century, examples in church artwork later. There are references to it in a couple of early 15th century Burgundian muster notes ( mostly commenting on the dismal state/ sever lack of armour for the lower legs ). Theres a really nice set of mid 14th century splinted bracers that recently came out of an olf well in Eastern Europe ( where it was more common ) andtheres a thread with pics of them over on the AA as I recall
Lastly returning to " who do you want to be " another example. The Hospitaller fortress at Rhodes fell to Turk seige in 1522. For whatever reason, the Turks had little interest in the armour in its armoury and left it there where it was discovered in the late 19th century and sold off over the ensuing 4 years or so by several European auction houses to museums and private collectors. A recent book reassembled as much of this maertail as possible into a single volume and reveals somethign interesting. The assembled surviving contents of the armoury included breast plates and armets c. 1410-1430 to pieces of the latest Maximillian armour and armour elements from every decade in between. Much of the earlier armour had " working life " modifications do to it to keep it in service. This was a working fortress on the forefront of battling the Turks in the Mediteranian, they weren't hanging onto the older gear for posterity they were using it. Not the top of the food chain guys, the other guys. Who you wish to be is as important because it can mean something very different in a given decade depending on social rank/importance and region in terms of what you need to get.
