Michael Broadbent has tasted a vast number of old wines. Here are a few from 1944 that he tasted in the last several years. He rates on a star basis, with 5 star being top.
Ch. d'Yquem - 4 star tasted in 1998; Ch, Haut Brion - at best 3 star tasted in 1998; Giacomo Borgogno Barolo - 3 star in 1996; Delaforce Vintage Port - 3 star in 1964; Dow Vintage Port - 3 star in 1961; Charles Krug CS - 4 star in 1985; BV Georges de Latour CS - 3 star in 1999;
It might take considerable time to locate any of these that have been stored properly.
I have a single bottle of Porto Guedes, Port of the Vintage 1944. The back label says: "This rare Port was stored in oak casks since the time of the vintage and bottled in1969". It was imported by John Gross & Co, of Baltimore MD USA. The back label also says: "The grower and exporter give their assurance for the year indicated on the label, and declare that his Port Wine was accompanied at the time of importation by a certicate issued by the Instituto Do Vinho Do Porto attesting the authenticity of the Vintage." Despite all of the verbiage on the label, this wine probably is nothing very special. The term "Port of the Vintage" has not been used for many years and has been replaced by "Colheita". Usually such a wine is made in years that do not produce many or any Vintage Ports. I mention all of this, because you might find a "Port of the Vintage" from someone else from 1944. I have no idea if "Port of the Vintage" was ever used in countries other than the USA. Perhaps someone from the UK, Canada, or Australia would know.