We have often been told that the green front bunkers in the GA were placed 10-20 yards in front to allow a carry. Obviously, if we believe there was more run up back then, then we have to believe the gca's left most, but not all, of the green fronts open.
I hear people say that the golden age guys used reverse slope greens more, but I don't know that I have ever seen a lot of actual evidence of that in the old courses I have seen/played. And, if balls ran more, it made sense to slope towards the golfer more. Running away would seem almost impossible to hold, and I don't recall any writing saying a well struck ball shouldn't hold the green.
White Bear Yacht Club has one (no. 12) and Riv struck me as having many "planed" greens (no rumples, but pitched all in one direction) but not always to the front, sometimes to the sides.
There are others, I suspect, and I recall some writing about it - not sure who wrote about the well placed knob in front of a green - hit the front and scoot back, hit the back and careem off the back of the green, but land short and roll over, and it can be well played shot.
Actually, though, I suspect that back to front sloped greens were pretty much the norm, with other slopes thrown in for variety, but would be willing to accept being wrong if someone better traveled than me actually could name a bunch of them.
Is the "front to back" green slope more a gca.com myth than reality?