Shakos

There are a TON of french shakos, all of tehm beutiufl, but I don;t know what shakoes goes on whom, can someone link me a guide? Did every regiment have its own shako badge and thats why they vary so widely? There the french eagle, the diamond, and its very confusing.

pre 1812 unifroms post 1812
As the french army had supply problems, causing the adoption of the 1812 uniform, which was less complex, although no less smart. Were there any account of some soildats wearing the old uniform at the time of waterloo?

BAtllions
Did french battalions of the same regiments fight together, or apart, sorry I've asked before but I cannot for the life of me find an answer? Most OoB say the name of a regiment but not its bttn number.

Thnx