I have pictures of mine at idle if you guys need to look at them. The fuel wouldn't really help (for it I'd just fill the car all the way up and move the needle to the F line...wouldn't be exact but close enough).
Oil and volts just center up when the car is idiling. They're just glorified idiot lights anyway and don't ever fluctuate/move. There's an article on mustang world that explains the hec diagnostic and that's how I set my fuel by guesstimating what the hec said to what the gauge should read. Speeo and tach were set by the hec as well.