I need one of you Browning Auto 5 experts help me figure out an Auto 5 20ga. actual worth, or maybe one of you that may be interested. This belongs to my brother. The serial no. is 76Z84934, but the barrel has this no.S 94854. Has a 28" vent rib barrel with mod. choke. And also has light twenty on receiver. Bluing is 98-99%, and wood is 97-98%. Thanks in advance for your help.