Yeah, the ones on the show (I think there were three) were the only ones Flying at the time.
There is one that was restored owned by The William Lyon Museum next to John Wayne Airport in Orange County, CA.
I used to work right next door.
Years ago I ran into an old guy who flew one in the South Pacific in WWII. He loved that Plane even though it had some “issues”, like not being able to pull out of a steep dive until they added Air Brakes on the “J” Model (I think).
On that episode I’m pretty sure it was two.
Beautiful, polished aluminum. Just glowing and shiny.
The story is one of them is a hotshot and he gets shot down by the end of the show.
Found it - in fact it was called “Hotshot”
http://www.imdb.com/title/tt0517369/
Apparently Red Bull has one