replace crank

This looks potentially like an Andersen Casement Operator, like the 39-094 & 39-095, or the 39-146 & 39-147. You'll need to compare both sets with your old hardware, including the arms, to see what matches best.

See the video below. You will need to remove the wood trim to get those screws. Though the video below features a different style of operator, the principles should essentially be the same.