Below you will see Frank the Welder's '82 Regina Corsa, which I'm guessing looks very similar to Squirtdad's Regina.



Do you see the two holes in the retaining ring at 3 & 9 o'clock? Find a punch which fits in those holes and a hammer. Grab a container which can fit over the freewheel to the spokes.

With the wheel in your lap, lean it against the wall or your bench so that it sits at about 60 or so degrees. Place the punch in the 3 o'clock hole in the retaining ring and begin striking down towards the floor. The ring has reversed threads. Eventually the ring will loosen. If it doesn't, soak the threads in penetrating oil and leave over night.

As the ring unthreads, move the wheel into a more horizontal position, and when the ring comes off, place the container over the freewheel, flip the wheel 180 degrees while holding the container tight againts the spokes. All the bearings, pawls and outer body will fall into the container.

You should now see the inner body attached to the hub. It should look something like this:



Using a big pipe wrench or a vise you should be able to unthread the inner body from the hub. This will most likely destroy the inner body.

But the pawls, the springs, the cogs, the retaining ring, spacers, possibly the bearings, and the outer body should all be saved. If you can't use them, I'll be glad to keep them for spare parts for future repairs. I'll be glad to pay the postage or send you another freewheel in trade.

Take a look at this picture. As you can see, the pawls and springs are critical, and as far as I know, there is no source to buy new ones.