caradco window replacements parts

arm # is 20755 on each

see pictures of latches
how does one attach the latch for the window - some of our window latches do the following - open the latch it locks the window and when the lever is closed it opens the window - eas it put in wrong (obviously) - how do you correct this problem - are latches made right and left side of the window? - I can't figure out how to correctthe problem - what is the part number for the latches that we would need if have to replace them