Williamstown Racecourse–ruins speculation

I went for a walk out there today and paid more attention to the ruins. Not just the obvious things, like the rubble with the steps and the single tree, but the less obvious items. I came home and looked at both the Google Earth view and the excellent 1930s aerial photograph. Here’s my first cut and what might be what in the ruins, starting with the photograph with some markers added by me:

And here’s my Google Earth snapshot, with the same markers:

The main rubble pile (with steps) is marked as A.  I used this as my starting point as I think this was the main grandstand.  E seems to be a building at a right angle to the creek, with D parallel to it. My white line over the creek is my guess as to the location of the bridge (partially) shown in the picture. It seems this was the end that was the main entrance. 

The tree position is pure speculation (in or near what looks like a ‘birdcage’ type parade area?), but my bridge (in Google) seems to “point” roughly at the tree. In the photo the bridge seems to be an extension of a road. No surprise there. But which road?

Next steps: find proper maps, plans or descriptions of the exact layout of the Track and it’s entrances. I’ll probably use Trove (online) and contact Racing Victoria. But any other information warmly welcomed.