Sorry, no, not rare. Just old. Being old does not automatically mean high dollar (or I would be worth a freakin' fortune!)
The value of ANY gun is based on exact make, model, condition, and originality. In the case of very old guns, the difference between a 75% finish and a 100% finish (like new) would take your breath away.
In fair shooting condition, yours would be about $100-$125.
What we have here is... failure- to communicate.