That's certainly taken a beating!
For what my six eggs is worth, assuming you don't want the machine to run at the max 24/7....
I'd get an infra red thermometer and warm the rod with a propane torch up to somewhere around 650 degrees c and hold it there for half an hour or so then wrap it in an old fire blanket and let it cool slowly.
Make up a couple of dummy shafts, for the big and small ends and then take it down to the local fabrication shop on a Saturday morning and slip the boss a tenner to push it about in a brake press until the dummy shafts are as close to parallel in all aspects as you can get.
Clean it up, give it a good thick coat of inspection and if you have access to the kit, crack test it. The guy in the fab shop will probably let you have a couple of squirts, to save buying the whole kit.
https://www.ebay.co.uk/itm/Flawtek-Weld-Metal-Crack-Flaw-Detection-Complete-3-Part-Kit/141181661281?hash=item20df153061:g:KIQAAOSwHfxdlzbkAs an side, you don't half get a lot of interesting stuff when you check eBay for 'Crack testing kit'!!
Based on a good outcome I'd be tempted to run the machine at half then two thirds power and if the rod doesn't let go then I'd live with half power from then on.
That would give you a cheaper start up and if you are happy with the machine and want more from it you can swap the rod out at your leisure.
Cheers
Stef