Remington Nylon 12 BA

[Shootingfun+44]

Hello,
I just got back my first rifle my Nylon 12, my dad gave me this after his father my grandfather passed away, I was only 10 at the time. Then at 18, my stupid dumbass traded to a good friend of mine for a Playstation Video game console. But after giving him a deal on a rifle that he was looking for that I had he let it go back to me.
Sadly though the rear sight is now missing cause when he had it he had someone put a scope on it and now he cannot find the rear sight, and at this time I cannot find one anywhere in stock either. So if anyone out there has any information as to where I can find one, and I know they are rare but don't want to charge me an arm and a leg to get this heirloom back to its original glory, please let me know.

I am so excited to get my first rifle back in the family.