0.3 is plenty close to 0. If you touch your meter probes together, you'll probably see about 0.3 ohms.
Terminal 22 is telling you that your power transformer screws need to be tightened.
Terminal 13 is measuring correctly.
Terminal 6 would be a major concern, but I don't see anything in your photos that would cause that issue to happen. I would double check that one. Definitely don't power the amp on though if it still comes up as 0 ohms.