Originally Posted by
merziac
Is there another tool with bigger notches that could be used after enlarging the ones on the Regina?
...This is one of the things that can have a very steep learning curve.

As far as a removal tool with larger notches, there might be, but I can't recommend one.
The Dura Ace two-notch removal tool is the best since it has the collar which fits snuggly around the soft metal Regina flange. But if the notches are already buggered, the entire flange is compromised, and I personally wouldn't want to install such a freewheel on a bike I'm out riding.