I have a like-new New England Custom Gun aperture sight for the Ruger scope-mounting system for sale. It will fit the 77, 77/22, 77/44, 77/357, Number 1 or any Ruger rifle or even handgun with the scope cuts on the receiver. These go for $90.00 new. They stay in zero if taken off and remounted. Would make a great backup or primary peep sight.
$55.00 plus $8.00 shipping.
I can't get a picture to load, but it is this sight right here:
https://www.newenglandcustomgun.com/proddetail.php?prod=6128