[Jeffhs]

I noticed a yellow wire disconnected in the picture of the chassis. If this goes to the antenna, you will have weak or no reception except on very strong local stations, and even then I wouldn't expect much. It may use the antenna as part of a tuned circuit, so if the former is disconnected or missing, the radio will not work. Think of car radios. These absolutely will not work without an antenna, even if you are parked in the shadow of the tower(s) of a 50kW station.

I don't see anything connected to the loop antenna in your radio; I'd reconnect it. I wouldn't be surprised if you get all sorts of stations, at reasonable volume, after the loop is properly connected.

BTW, I noticed one Panasonic battery in your radio among three industrial-grade batteries of another brand. Mixing different types (brands) of batteries in radios, or any kind of battery-powered device for that matter, is not recommended. You mentioned that the batteries in your set aren't weak or dead, but if you have two or more different brands of batteries in it, one or more of the mismatched ones may be weak or even stone dead. I'd replace all batteries with fresh, new ones of the same brand. Again, it wouldn't surprise me if you get all the volume you want, and then some, from the radio with all new cells.