Just be patient when hunting for parts. They turn up sooner or later.
Dug out some of the mustangs, and here are the alternator and binaltech side by side:
https://imgur.com/a/SyGLYXl
As you can tell, there's no visual difference between them aside from the chrome on the binaltech (the difference is immediately apparent when you pick them up, though), so finding a junk or broken alternator version for parts would be fine. You'll notice that the same part on my figures is slightly 'off' as well. Not sure if it's age related or if I just never noticed it without me attributing it to mistransforming the figure. Either way, it seems I don't have good copies to send you (which is fine because postage to Israel would be too much anyway - the USPS website says even the smallest of boxes and envelopes cost $36 minimum).
I'd try the above suggestion and heat the part to make it pliable, and then gently bend it back into shape. You could try a hair dryer, or you could use pliers to hold it in boiling water for a short amount of time. No matter the method though, please test it out on something broken first! No reason to find out the hard way whether a method works or not.