3run: It may well help with the stitching later, if I can get the entity
vertices to follow the same numbering structure as terrains, but it contains
nothing to help me at THIS stage.

Progger: I see what you mean, but its just not feasable dude.
When Im potentially moving a terrain by up to 2,000,000 quants in both
the X and Y directions, the maths will get pretty ugly. And thats assuming
Also, having a terrain with vertices as much as 1,000,000 quants away form
its origin could possible cause some serious performance issues, or odd
collision-hull behaviour...