1963 White Wines
I'm sorry to say you're not going to find anything wonderful, maybe not even drinkable, at any price. Not white wine. Except for stickies.
If you've got the $$, I'd recommend the 63 Vintage Port, which is outstanding. and for always was the only thing from that year that was ever any good. I have the same dilemma. 63 was my bacalaureate year. Just TRY to find anythink drinkable from then, even 10 years later... Impossible.
What's your budget?
The only California winery that made Chardonnay in that era that might still be drinkable was Hanzell, but Jim Zellerbach died in August 1963, and I'm not sure anyone made wine from that vintage. After Zellerbach's death Joe Heitz bought some Hanzell Chardonnay and Pinot Noir in barrel and bottled them, but I think those were 1961 and 1962.
Conceivably there are white Burgundies, Sauternes, or BA or TBA Rieslings from that era that are still drinking well, but good luck finding one.
Best bets from that vintage would be Madiera, Port, or Armagnac.
K&L has six ports and a two-bottle set of Sebastiani Cabernet Sauvignon. The latter could be very interesting for a wine geek since they were still using redwood vats.
JJ Buckley has a lot of 1963 Croizet Bages in magnum.
Rare Wine Co. is a good source for old bottles, but they don't currently list anything from 1963 in their online inventory.
Astor has a couple of Armagnacs:
wine-searcher.com/prof finds some interesting stuff in Europe, for example a 1963 Antinori Vin Santo:
Good lord WHY??!?!?
Yes, it's for a 50th birthday present; I understand that. But even the greatest of all Chardonnays -- Grands Crus Burgundies from fabled vineyards like Montrachet, Bâtard-Montrachet, Corton-Charlemagne, etc. -- from the greatest of all vintages will reach its peak of maturity in 20-25 years, and even that is pushing it.
Safe bets for 50 year old WHITE wines are sweet dessert wines like Sauternes (Bordeaux), Vouvray Moelleux (Loire) and Sélection Grains Noble (Alsace) from France; Beerenauslesen and Trockenbeerenauslesen from Germany; and Tokaji Essencia from Hungary.
But 1963 was a pretty horrific year for everything in Europe -- it's a tossup between 1963 and 1965 as to which of the two was the worst European harvest -- EXCEPT for Vintage Porto, where it was the single best vintage between 1955-1970(!), and that's a fortified red!
1963 wasn't very good in California, either, and although there are few absolutes in Life, I'm willing to say absolutely that no 1963 white wine from California will still be in good (let alone great) shape . . .