Good luck in the search.
The Unique Car mag and the Just World car magazines run adds from Mustangs of Melbourne etc.
Check out their adds.
Have heard a few good reports on a Sth. Australia company, I think it's called Rainsfords or similiar. They import to order and convert to RHD for under $5,000.
I'm over in the States in a few months and if you still looking I'll check out a few friends that have contacts there in clubs and cruiser clubs...
They after all just '66 XP Falcons..
..there. But are now starting hard to get.
Bernie