What kind and how old is this knife

[Mountainking7328]

What kind and how old is this pocket knife it has no markings on the Tang except for a number 5517 has four blades and only one blade has a number on it all the rest are blank

 

[EngrSorenson]

What kind and how old is this pocket knife it has no markings on the Tang except for a number 5517 has four blades and only one blade has a number on it all the rest are blank

A picture would be immensely helpful, but I googled it on a whim and came up with, “John Primble Belknap HDW & MFG Co. 5517 Delrin Big Congress Knife”.