Sargent 407C vs 5407 Confusion vs Clarity

I recently acquired a Sargent smoother commonly referred to as a 407 but in this particular example the bottom has a thin casting, single piece brass depth adjusting nut, horseshoe lateral, second trademark with the "USA" stamped in the middle of the oval and 8 corrugations. Available existing research says that this may be a 5407 but that should sport a two piece brass nut with a steel core. Everything else adds up. OK, I’m a bit confused then...or maybe not so much.

According to David Heckel’s book on Sargent planes the 407 with the thin body and horseshoe lateral was produced between about 1891 to 1909 but the corrugated version didn’t come out until 1907 and that was the 5407, 8 corrugations, 2 piece brass depth adjusting nut with steel core and rosewood. Then in 1910 the 5407 became the 407c with the number stamped into the iron. So, thin corrugated body, horseshoe lateral, single piece solid brass knob, 407 cast into the body, second type trademark on the iron. Heckel also said that the 5407 didn’t have the number cast into the body but this one has 407. Perhaps he only meant that the "5" is absent as 5407 was in fact simply a catalogue number that Sargent used to diferentiate the corrugated from the non corrugated.

So, 407 or 5407? I’m going with the 5407 because it means I got a pretty good deal. Just kidding. The wood is in fact rosewood, the knob has a bead and the tote has the "chunky" look of the early Sargents. It’s the first horseshoe lateral I have that doesn’t have a crack at the corner of the mouth. The one-piece brass knob is bent but serviceable, it’s dirty and a bit rusty but otherwise intact. The frog doesn’t appear to be milled or at least obviously. It looks like a pretty clean casting. Don’tcha lova mystery?? But I digress.

"NO MAS CONFUSI'ON" So I have a friend, a veritable expert on Sargent planes, who not only has a sizable Sargent 407/5407 collection, but likely every other No 2 plane ever produced. I'm sure he would disagree with that estimation but it's probably close. After hundreds of observations of both plane models I believe him to be as I described, He explained to me the following:

"You have a 5407. Not marked with the 5. The brass nut is right if it is brass. 2 piece nut was next type. Either would be correct. Easy. Thin casting, 8 groove, 5407. Some will have the second lateral, but all are 5407. The 407 has 7 grooves and thicker casting. What you need to make it correct is the chunky looking rosewood tote and rosewood beaded knob. The lever cap is smooth face with 407 and the recessed dot on the back. No dot. Pre-lat. Fat sides on the rosewood. Pre-lat. The early adjuster nuts were solid brass! In fact the earliest Sargent 407s (pre-lats and first horseshoe) had a solid brass single line nut just like Stanley 2. Then came the solid brass 2 line nut. Then the 2 piece steel and brass nut, then the brass plated steel (small) nut then large steel nut. That is the order of things. I wish someone would write this all down before I forget it!"

OK, someone just did.