I'd say the top 100 pre- and post- would be very close in quality.
Lido, Timber Point, Laksers, Olympic-Ocean, CC of Havana and CK Hutchison's Turnberry -- these lost courses would very likely be included. Plus you must consider improved San Francisco, Pebble Beach, Bethpage, Yale, Riviera, Bel-Air, Cypress Point, ANGC and a number of Thompson's courses - some significantly improved.
The top 200 to 250 swings decidedly toward pre-War.
Lost courses like Addington-New, Royal Montreal, St.Peters-Mablethorpe, Tailor's Ocean Links, Cedar Bank, Boca Raton, Knocke, Princes and Tokyo. Improved courses Sharp Park, Lakeside, The Broadmoor, Manoir Richelieu, Hayling, Alwoodley, Moortown, Huntercombe, Hollywood, Engineers, Oyster Harbors, Ponte Vedra, Brook Hollow, a number of courses on the European coast, a number Heathland courses, the most famous Japanese courses and a number of the courses of the more ecsentric architects like Emmet, Strong and Travis (that've either been dumb-downed or lost all together).
After the top 250 or so the edge would probably go back to the post-War. Fifty years of courses is hard to ignore, especially the last ten.