Yes, of course a Classic layout can also make the list by new raters voting on it, or by raters reassessing their old votes and voting again upon a second visit.
Jim Nugent, I am adamant about not moving the line; I've written too much about why 1960 makes good sense. I get the reasoning by shifting the line at some point, and I'd be more tempted to do so if there were going to be as many new courses coming on line in the next decade as there were in the last decade, but that won't happen now given where golf development is going. So if it stays entirely up to me, the answer is "no."
Urbina, the NGF data on course construction 1932-1950 are not there, as I recall, and as you can surmise the numbers are nearly negligible. I can look up what I have when I get home and see what I can come up with.
Brad