Ashburton (or, as he spells it, Asburton) has been modelled by razor: <kuid:78778:100059>
I've downloaded it with TANE (faster & no 100MB per day limit) & imported it to Trainz2012. Like always, some assets are missing, & unfortunately the track is one of them.
But there is also an amalgamation of this route with another one of razor's (Windrush <kuid:78778:100021> or Windrush V2 <kuid:78778:100212> ), named Ashburton (now with the 'h') to Windrush Railway V2 <kuid:234086:100617> , & here the few missing assets seem to be nothing too important.
The trackplan of Ashburton Station in these layouts looks very much the same like the one above.