Looking for parts

My windows are alum. frame , they have a lip on the bottom of the glass frame , they have a two piece handle that is spring loaded , bottom frame has a slit that the handle locks into, the handle is alum. the second piece is a pop metal with a hole on the outside on each end the latch has a round piece that sits in these hole , it pivots when you lift the handle allowing you to unlock and open the window, these were installed in 1968