Ok I have just aquired an old Honda that I'm planning on restoring and it has no compliance plate fitted ( it's a 74 model ) but it has a modification plate on it from 1989 and the code is C1 , they haven't used these codes for years and only keep records at the mod department of QT for 6 yrs so they can't help me . Does anyone know what the old codes mean ?? And I already know the code is for heavy vehicle drivetrain but thats under the newer code system . It has the vin number stamped on it and the engine no matches but I just want to know what this mod plate is for .....Anyone ??