30 years ago, I don't remember rangefinders as common and I always used parallax on my Diana rws 48 with I think it was a Bushnell air rifle scope.. been so long ago I don't remember the model or the magnification range.. I just remember it was a good scope at the time and not competing, just target shooting and hunting ground squirrels it was very accurate..
now everyone seems to have a electronic range finder..
I did find it interesting in a catalog, recently I saw a new brass copy of the civil war era range finder and it was a veneer scale and you just sighted through the hole and adjusted its size to the height of a man.. and then I guess you used elevation settings on your open sights to be on the first shot..
it's always great to see and learn more... whether new or old ideas.. as long as they work..
Mark