There were 3 different types. All of them had the Guards compartment in the centre, and accommodation for traincrew in one end. The difference was what was in the other:
TGV,TGVH,TGVS: These had a goods compartment in one end. TVG's & TGVS's had sliding door access to this compartment. TGVH's had roller doors.
TDV: This had a Drovers compartment, comprising a toilet and a bunk/seat.
All the above were the same length.
TLV's were longer. They had a passenger compartment between the traincrew compartment and guards compartment, and also had a goods compartment. These are the vans which worked most of the last generation of mixed trains - Hughenden-Winton, Emerald-Yaraka, Maryborough-Monto. Their underframes were used for the GSPE set, which carries their original van numbers.