I found this at Grainger for $5.67! 1 Meter long! You can cut it to whatever size you want. Just taper off the cut end on your new grinder to grind off the damaged part of the thread so you can get a nut on it. Or you can run a nut in from the factory cut end and out the end that you cut to chase the threads.
https://www.grainger.com/product/Fully-Threaded-Rod-M5x0-8-38DK86
And the sell left-hand nuts for $1.61 for a bag of 50.
https://www.grainger.com/product/Hex-Nut-M5-0-80-Thread-22YK31
There's a Grainger in Portland, if it's not far from you. They don't stock it, so you'll have to get it shipped to you or the store for pickup.
P.S. I got the IMSB tool back, thank you.