Sarreguemines is a French town on the Sarre river. The river is the border delineation between France and Germany. On one side it is French and the other side it is German. Historically the town has passed between France and Germany a number of times, most recently passing over to France after WWI. Schweitzer is not an overly uncommon name in the Alsace-Lorraine area of France. The bike is definitely a French bike.

PS: Sarre is the French spelling for the river that is also often known by the German name Saar.