Undercutting Brescian-style f holes

[Presumin Ed]

I am currently making an instrument based on a Brescian pattern.   One thing that I am contemplating doing is undercutting the f holes.   Gregg Alf mentions this on his blog, and John Dilworth also alludes to this practice in his writings.

 

This is not something I have tried before, so I am interested in any tips or advice that others may have on this.   My assumption is that I am aiming at the kind of profile depicted here in the Courtnall & Johnson book:

 

 

One question that occurs to me is whether this is applies all the way around the f holes.   The reason for the question can be seen in the attached picture I took of a Maggini violin:

 

 

To my eye the wood around the upper eye does not appear to have been undercut.   For comparison consider the wood near the f nicks.    Is this variation significant, or not?

 

As I say, any help you can offer gratefully received.

Cheers,

Ed.

[Torbjörn Zethelius]

I don't know enough about Brescian instruments so take this with a grain of salt. But consider that the hole was cut with a drill while the rest was cut with a knife. The knife can be held in any way while the hole need to be cut perpendicular to the grain, more or less.

[Conor Russell]

I make Brescian style violas. I just cut the holes, and then bevel them back with a few stroked of a knife, leaving about a mm of edge. I darken the edges, and the thickness at the loops isn't obvious.