Two Way Screw? Question About Tail Stock Screw On Power Kraft Wood Lathe

I got a old Power Kraft lathe from a buddy who inherited it for a relative who passed away. The screw that runs into the tail stock must have gotten bent and mangled up at some point. It's been cut short and is in rough shape. I plan on replacing it but am stumped. It appears to be two way threads or some sort of cross thread. I was curious if anyone could tell me what this is? Why they used these threads vs standard? And what is the best/easiest option for replacing it?

That looks to be an Acme thread. Left hand on one end and right hand on the other. Maybe parts are available from somewhere. Failing that, the only option is to make one if you have a metal lathe, or have someone make it for you.

The threads the handle screw into are pretty normal. It's the threads that screw into the tailstock that are odd ball (at least to me) In the attached picture I zoomed in to better show you. The threads are kind of zigzag. The best I can describe it is a two way screw. I'm kind of stumped on the reason for it and how to go about fixing it. I'm tempted to bore it out and thread it for standard threads. I figured I'd better hold off until I know more about it first.

I couldn't figure out how to add/edit the original picture's but if you zoom in on the last picture from the original post you should be able to see what I am talking about. Zoom in on the threads on the bottom half. Instead of a constant spiral all the way around they are made of separate zigzag threads.

It looks to me like it was installed backwards at one point and cross threaded. It looks like the long end is supposed to be left hand threads, and the short end is a right hand thread. There should not be threads going both ways on the long end.

Originally I was wondering the same thing but after a closer look you can tell they were definitely cut that from the factory. Our metal fab/welder at work said he was slightly familiar with the thread design and mentioned something about them being able to lock in place or something like that. He wasn't very confident in his answer. I am probably going to scrap it and rethread the tailstock for a standard bolt.

Could this be some special thread to prevent backdriving?