Coordinates & units

Hi Tim

I have a question about coordinate systems and units. I have imported GIS info from Sydney into Grasshopper using 2 different methods. Firstly using Flux Site Extractor and the second using Elk 2. Both of these, as far as I understand, use Open Street Map data which is WGS84. However when I superimpose the same area in Rhino I am finding they don’t match up.

Firstly I need to scale the data down by 0.001 presumably from km to m (or from m to mm???). And secondly, after the geometry has been scaled down, there is a discrepancy of 708.61m E/W and 217.52m N/S. There also looks like a slight rotation or scale difference.

Am I missing something? Since they both come from the same source and hence coordinate system, shouldn’t they align.