Excellent information. One of my tone control knobs has a circle of red glitter wrap on it. Is that also from the later period? I sort of like the egg shaped tone control knobs from the earlier era and may use them if I use any at all. Quite possibly, I'll just remove the tone controls for the time being. I don't know if it shows up in the pictures, but the floor tom hoops are tapered inward, but the rack tom hoops look normal. Wondering if either set is not original. To me, the rack tom hoops look like Ludwig. ThanksJim
The tone control knobs with the matching wrap insert are from earlier but were used up until 1967. Usually ,on those, the earlier system was used with the thread inside a through hole in the knob, which pulled on a J rod fitted into the spring muffler. The later ones had the knob , fixed to the shaft which threaded into a short rod shaped nut, which pulled on the spring mufler.
The older knobs you are referring to , were only on the bass drum. They looked exactly like a bass drum T-rod handle. They were never used on the other drums. Those had a little threaded chrome knob , very similar to the ones used on Premier and some Slingerlands.
In 1967 ,Trixon switched from a hoop , with a slight incurve( the ones on your floor tom) to a triple flange type , similar to a Ludwig hoop.
Drums were shipped to the distributor, from the factory in individual boxes. It was the job of the distributor( mostly St.Louis Music, in the U.S.),to order enough drums to assemble kits , according to orders from the catalogue, or in some cases as custom orders.Individual drums could also be sold, which might leave a missing drum for a specific kit. This kit was put together, with drums from different production dates. The floor tom is likely 1966,even earlier, possibly, bass drum likely 1966 but the other two drums are 1967 .
With these few crossover features, it probably dates your kit to a 1967 sale.