You can put a stock type reproduction window handle if you file the shaft so it has a square end. The stock handles on those era cars had either a cross pin that was a snug fit, and held in by the escutcheon, or a screw through the handle that went into the end of the shaft..Are you looking for a repro or fancy handle?
A description of the actual mechanism would be helpful in determining which way to look for handles. There were aftermarket suppliers of universal mechanisms to the body manufacturing industry. Folks also installed whatever they could find , as many of those 'glass bodies came with no hardware for windows.
Later, mikey