The kerf on the Stanley handsaw is about half of the big saw, which means the big saw tends to want to jump around a bit. I'm wondering if, on those old timbers, they kerfed in with the small saw, then chiseled out to the line to give the big saw something to ride against. I'll have to take a look. Some of those shoulders on the anchorbeam tenons are over 20" long, a real pain with a short saw in fresh pine.
At the geometric design workshop, I saw some people cutting to the line with a two man crosscut, but I don't know what method was being used to start the saw. I do recall the cuts came out to the line. Gabel or Tim, or anyone else there, do you remember the process for using that saw?
I'll be playing with the tuning of this big saw over time. I want to find or make a raker gauge and a spider gauge for measuring the set. I think I'd also like to stone the backs of the teeth like Tim mentioned. The saw was originally black, it was rusty so I cleaned it up with a flap wheel on the angle grinder. The teeth aren't pitted, but the saw is still a little rough.