Joined: Jan 2009
Posts: 43,982
Likes: 6,169
From: New York, NY, and High Falls, NY, USA
Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem
In other words, this concern has dried up. All freewheels fit all hubs unless you have something old on your hands.
Since your existing English-threaded Regina freewheel fits on your existing hub, a new freewheel will fit your hub.