Adopted Dog Neutering question

Hello, I have adopted a dog earlier this week and plan on taking him to the vet in a few days but I'm kinda confused about my dog right now. On my dogs medical records the place gave me, he is listed as neutered. But when I was filling out paperwork before getting him, they said I needed to get him neutered. When I look at his testicle area it looks like there is only one, but it also had markings like they had done a surgery there and additionally the sack looked slightly deflated and has light scabbing like there was, but still big enough to be noticed. It is kinda confusing me and he doesn't really align with any visuals or posts I've seen online. Any answers for right now to help me clear up any misconceptions I'm having?