Apologies, I uploaded the wrong photo here. The 1937 one of Scribban should have been an old photo that was taken looking up to South Tower Corner from The Alley, just north of Maxim Rise - where the modern day one was taken. The photo (which was saved from somewhere or other on t'internet many moons ago) seems to have vanished, but I'll upload it when I find it.
Regarding the photo that was uploaded, my understanding is that Konqi is correct and that the photo from the first road racing meeting was taken from the inner loop, at the western-most point of the south side of New Zealand Hill, looking north-west towards Scribban heading south-east down New Zealand Hill after having just navigated Big Tree Bend, overlaid on the map below.
There's another in the book, shown below, that shows Raymond Mays at the same race just approaching Stadium Dip, with the same backround and you can see exactly where that original Scribban photo appears to have been taken from. Much of New Zealand Hill appears to remain as the link road from the sports centre to the Hexagonal Lodge Tower block (including most of Stadium Dip, plus the point where Stadium Curve joins with what subsequently became New Link is aligned with the access gates/gaps in the trees of New Link).
The current view from where the Scribban 1937 photo was taken is not really recognisable and is blocked by bushes, at the northern-most point of the triangular-shaped car park for the Lodge Tower block. I don't have a photo of it from that point (though I'll try next time I'm there), but you can see the bushes behind which that point is in the photo below, pretty much exactly where the lamp post is to the right of the tower block.
It's one of many endlessly fascinating historical aspects to this amazing park that many boroughs would cherish, celebrate and turn into some kind of visitor attraction that could provide revenue towards the upkeep of the park. Alas not here, though that's probably one for another thread.