YKK vintage heavy duty two zippers vs plastic zippers

Hi! While shopping online I have read many complaints about companies that have switched from metal heavy duty two zippers to using cheaper plastic one way zippers on expensive warm coats. And their customers are very unhappy if the zippers don't work.
I have two vintage jackets with real heavy duty two way metal YKK zippers. I was thinking of giving them away but now am having second thoughts. The reason is I can't seem to find out if YKK still makes these heavy duty two way zippers, so I am now thinking of removing the metal zippers on these coats so I could use them if a zipper breaks on one of our other winter coats. I would appreciate any information and thoughts you have on this. Thank you

 

Thanks for the idea of looking on Etsy. I am looking now and just learned that zippers come in sizes. Some I am going to find out the size of my zipper and look for it online. Thanks again!