A4 B7 2.0 Tfsi GVD Gearbox

I have a 2006 2.0 Tfsi bought as a pre-owned car, which has now  done 88k miles.     Never really hammered or abused the car.     Last couple of years 2nd & 3rd gear synchronisers have become slightly awkward to cleanly engage.   Other gears are generally hard.     I've changed the gear oil and bled the clutch using Audi brand fluids (expensive) but still no improvement so am resigned to the idea that I should either go to the expense of a gearbox overhaul or opt for a 2nd hand gearbox.

Mine is a GVD and there are plenty of them around via ebay and online generally.    What's emerging is the GVD gearbox has been used in a number of different models including A6 3.0 litre, more recent Cabrio's and the Seat Exeo.

So here's the question; given I'm looking for a low mileage replacement gearbox likely closer to 2008or 2009 are all GVD gear ratios the same ?     Also, if I get a continental GVD gearbox from say Sweden, Poland or Germany will I need to carry out any speedo/odometer output conversions or does this take place via the car's ECU mapping ?

Regards,

Jools