In this video made in 1984, two toolmakers for woodworking show how they were manufacturing their tools. At around the 9 minutes mark, one of them is seen flattening a wooden plane seat.
I think that we have here at SMC a few toolmakers and it'd be interesting to have their comments on the technique used.
The video is in French and I can translate a portion if required.
https://www.rts.ch/archives/tv/cultu...iframe-overlay