I've been searching for a couple days now, and the closest I'm coming to finding the right insert is a Time-sert (Big-sert) p/n 50155. The tech rep at Time fasteners says, "It's very close to an M14x1.5 external thread", but looking at this website (
https://www.wiseautotools.com/time-sert-50155-m10x1-5x24-5-over-sized-big-sert-replacement-insert/) they are measuring out much larger. A standard M10x1.5x24.5 Time-sert uses an STI thread that is much smaller than an M14 thread. Closer to an M12.
I'm running out of ideas. I called our host directly and they definitely don't stock these and referred me to Time-serts.
EDIT: Additional note. I did look up the part directly that the PET shows (N 022 202 1) and had a dealership look up the P/N to see who currently might stock it, and he said nobody in the US currently has it listed as in stock. Only Germany. If that's what I have to do, then so be it, but it's listed as a "helicoil" and this does not appear to have a thread for a helicoil. I don't want to order something from Germany only to find out it's not right. So if anyone has any information on THAT, it would be helpful.