Bob,
I have Stanley Thompson's routing plan for Green Gables here, in my office, along with some historic photos of the course taken around the time of its completion, c. 1940.
The dunes holes there, on the north shore of Prince Edward Island, appear to have been really neat. Problem is, that section of the property has been partially erased by ocean tides and severe storms. In fact, the dunes holes were eliminated not very long after they were opened for play because of recurring damage.
So, true restoration of Thompson's Green Gables is, for the most part, impossible. However, there is some potential for the inland holes, especially where some really neat original Thompson greens survive. I noticed a few greens with excellent contour when I was last there in spring 2006.