Photo's would be a great help. Basically but not always, carbines came with three different rear sites. From serial number 0 to @900,000 they were issued with a 2 or 3 leaf express sight. From serial number 900,000 to 1,300,000 most were issued with the later sight. From 1,300,000 a leaf sight with a elevator was standard issue. HOWEVER, I am basing this on the timeline when Winchester changed rear sight dovetail locations. Again a good photo would be a big help.