I came a crossed a portaflex and the serial number is in the range for 1965. I need to find out why the name plate that has Ampeg etched on it also has the name Walter etched on it. The etching looks to be factory. There is no one named Walter in the family history. I need to know if this is significant in any way. I am looking to purchase this and restore it to its original glory and want to make sure of it's value to make a fair offer . Any old-timers/historians here know the answer?