27” Grande. In search of replacement top!

As the title and the photo shows, I am missing the top piece to my 6821 27” Grande lava lamp. I’m not the original owner and it didn’t come with the top piece. I see you can buy 3D printed ones on eBay but they are pretty pricey and sold out anyway. I’d rather go the route of getting something other that 3D printed or maybe just putting something else on top in the original lids place? Any ideas? The top measures 3” in diameter. Thanks!