Re: US Open Results
The Hall of Fame is incorrect in this instance. Pancho was only the RU in 1943 and 1947. I double checked this against American Lawn Tennis and Dunlop's Alamanac. I even triple checked-Bill Talbert's autobio records his wins with "Ozzie" and seals the deal.
Per Dunlop's, Segura obtained a US National ranking as early as 1942. He was ranked #4 in the US (1942) #3 for 1943,1944, and 1945-and #9 for 1946. His Us rank for 1946 kept off off Davis Cup even if he were eligible, and Ecuador didn't contest Davis Cup in 1946.
Dunlop's lists him as "Ecuador" at Wimbledon in 1946.
If you send me a PM I can search a database in a couple of days to check his citizenship.