Tubby,
The 'code' on the panel gives its location. Since you are already looking at the panel, it tells you nothing you didn't know already.
123AB 'decoded' means;
1 - zone (1 - lower fuselage, 2 - upper fuselage, 3 - empannage, 4 - nacelles, 5 - left wing, 6 - right wing, 7 - landing gear, 8 - doors)
2 - sub-zone
3 - sub sub-zone
A - sequence
B - locator (T - top, B - bottom, L - left, R - right, Z - interior)