Ian
Ain't dat de troof!!
The Atkins saw I pictured in post #13 was a 5ppi rip saw progressively toothed. A single tooth was broken about three quarters of the way down to the gullet, which meant that the whole saw had to be jointed. Not down to a bare toothline, but close. There was just enough left of each tooth that I knew where they had to be. I did not have to get a paper tooth spacer out for that one. After forty strokes of each tooth I still had small flats at the top of the tooth. I did not do a final count as I had lost the academic interest by that stage. However, there were at least another ten strokes to go including sharpening, probably more.
There are times when a Foley Belshaw re-toother seems extraordinarily attractive.
The smaller teeth on a 10" or 12" backsaw are not quite so tedious and a much better project for first timers and probably most others too.
Regards
Paul