I encourage you to attempt straightening of the y-axis handle and lead screw. After all, if you are intending to purchase or make new ones, then you have nothing to lose in trying to remediate the existing ones. However, really think through the process and the steps. I have straightened prop shafts, large drill bits, the x-axis handle on my mill - every one takes a different approach. Usually I have to make a custom holder or tool. Go slow and think it through - it is pretty easy to get 90% of the bend out, and sometimes that is sufficient (the last 10% can drive you nuts).
Do you have a lathe? Lead screws are a challenging project, but within the capability of a novice person taking some extra time. I have made 3 different lead screws, the challenge is managing tool push on the last few passes. Perhaps the actual lead screw is okay, and maybe you could cut it off and stub in a new end?
Let us know how you make out. David