When I looked at the plane the mouth was a little wider than I liked and I wasn't happy sending it. This situation was resolved by fitting a brass mouth insert and this technique could equally be used on any wooden plane to bring it back to former glory!
The first step was to prepare a piece of 1/4" brass on the disc sander with sides dovetailed at about 10 degrees. The blade was then position with a small but even protrusion and the brass insert pushed so that it rested agianst the edge. I carefully knifed around the insert with a scalpel, going over my marks a few times in order to make a clear impression in the ultra hard Lignum Vitae sole.
I then set my laminate trimmer to slightly less than the depth of the brass and carefully excavated the waste and trimmed back to the lines. Note the protective duster in the jaws of my vice, I didn't want to have to refinish the plane as well!
Here is the finished insert with the blade set, now that's more like the mouth a fine smoother should have.
I used to make all my planes with a brass insert, I'd forgotten how nice it looked.