Liege United Arms Co shotgun

I have a full ckoke 168, Liege double barrel 12 guage shotgun. The serial # is 10003 and the model is a "Leader". I am looking for the approximent value of it or a way to find it out. I have one also serial no. 19203, 12 ga. 30" F& IC. It has engraving and looks like a Francotte. I have the same question!!!