If you want to get technical, then a proper scope for a 20's gun would be a Malcolm, Winchester 5A, Lyman A5, Belding&Mull, early Fecker, any number of German scopes, etc. (some of which are surprisingly good, but most would make the modern purist cringe).

"You can lead a man to logic, but you cannot make him think." Joe Harz
"Always certain, often right." Keith McCafferty