Battery part numbers

Hi.

I need a replacement battery and would really prefer an original. The one in my XPS 15 9570 is a 6GTPY but that is hard to find. I can find plenty of GPM03 that are listed as GPM03/6GTPY but are they really the same/fully interchangeable?

dell.dk does not list a battery for my laptop in their shop but dell.com has a W62W6. Several sites has batteries listed as 4K1VM/W62W6.

1. Is there an official Dell resource where customers can look up compatible/recommended part numbers?
2. Failing that, is there anyone with access to solid information that can list the officially compatible 6-cell batteries for the XPS 15 9570.

Thanks,
Tom