Does anyone on this site have one of the cube fixtures from the 1964-65  Worlds Fair in Flushing Meadows New York?

Not that I know of.

According to this site, there are some in active service in Orange County, NY. And supposedly some made it into the hands of collectors.

I originally thought they were Wide-Lite cubes but it looks like they're something else. I wonder what lamps they used...almost looks like GE's short lived panel F lamp.

Not that I know of.

According to this site, there are some in active service in Orange County, NY. And supposedly some made it into the hands of collectors.

Yes, I have been chatting with someone who has one. He did some measurements  for me. I want to build one, not sure which configuration yet.

I originally thought they were Wide-Lite cubes but it looks like they're something else. I wonder what lamps they used...almost looks like GE's short lived panel F lamp.

You are correct they had the GE Panel fluorescent for these cube fixtures.  The fixtures were manufactured by Westinghouse ( from what I have read about them).