gearbox serial no Fabia 1.4tdi Greenline

does anyone know if the gearbox on a 2009 fabia 1.4 tdi is serial numbered for identification like an engine ?

if yes can you please let me know whereabouts, (favour request) can anyone offer to help check against skodas list in north hants my fabia greenline 1.4tdi has been messed with and the gear ratios are much lower the revs are to high in 1st to 4th,

it would be nice to know what is in it now to help decide how to go about resolving it.

Chris B