Here are two documented French and Indian War Kidney Canteens.  One is from Fort Ticonderoga which was occupied from 1755 to 1777 and the other is from Fort Ligonier occupied from 1758 to 1766. 

They both are made from one sheet of tin. 

The Fort Ligonier canteen is one long strip for the body and the spout, top and bottom come from the left over piece.

The Ticonderoga canteen body is cut from two pieces and has an additional seam yet it holds an extra 4 ounces.