Man, as severe as that bend is, I'd be worried about work hardening it without first heating it up. My vote is not to cold set it, but take it to a metal shop. A little bit of flame to soften it up and it should be easily bent back into shape without too much stress. After it cools, you can fine tune the spacing and alignment.
It's almost certainly not heat treated, so you don't need to worry about that. It will nuke your paint, obviously.
Or do the hourglass stays and sell it on eBay for thousands of dollars as a custom track bike.