Peerless springfield

I wondering how much my handcuffs are of value. I don´t know a thing about handcuffs and it´s value. But it could be fun if someone could tell me. I found these in the basement of my dad´s work. I know that they used it in the 70´s or 80´s.

It says Springfield Peerless on it. PATENT: 1531451-1872857 MADE IN USA

A photo would help, but if there're the standard Peerless, they're probably worth about $15 depending on their condition. New ones go for about $25.