What data can be used with the engine?

[catalinc404]

What data can be used with the engine, searching the net it seems that the earliest release available is v205.
Trying to load entry.unr from version v205 fails in UModel.cpp serialization load "Leaves"

void UModel::Serialize( FArchive& Ar )
{
guard(UModel::Serialize);

UPrimitive::Serialize( Ar );

debugf("serializing UMODEL: %s %s", GetFullName(), GetPathName());

Ar << Vectors << Points << Nodes << Surfs << Verts << Polys;
Ar << LightMap << LightBits;
Ar << Bounds;
Ar << LeafHulls << Leaves << Lights << LeafZone << LeafLeaf;

Any ideea where to get data corresponding to this code version?