Definitely contact Walther directly @ 479-242-8500 EXT. 7 - Monday–Friday, 8:00 a.m. – 4:30 p.m

Hi Aaron, I highly doubt this part will be available for purchase. You can contact Walther, as others have suggested, but I wouldn't get my hopes up. You can always use a piece of black electrical tape to hold the battery in place.
Stay safe & have a great day!

You may be able to get a replacement dust cover from the company who manufactured it. If it was Walthers, just contact their customer service at 479-242-8500 EXT. 7 - Monday–Friday, 8:00 a.m. – 4:30 p.m

Hi Aaron and welcome. I would contact Walther Customer Service (if you have the Walther Laser), for parts availability at 479-242-8500 EXT. 7 - Monday–Friday, 8:00 a.m. – 4:30 p.m. CST or by online inquiry here: https://waltherarms.com/contact ------------ If you have a different brand, contact the maker's Customer Service. Cheers and stay safe! P.S. You can sometimes find used on Ebay for little $.