I arrived at a date range for these horns by extending the serial number charts into the "serial number black hole". At the very least, I can say that these horns definitely came before the next models, because:

- LH bell-keyed horns are less advanced than RH bell key horns and all manufacturers I've ever seen produced RH bell-keyed horns after their LH bell key-keyed versions, if they had them at all.
- The logo is more reminiscient of the "Series V" horns, whereas the "Series VI" horns have engraving that looks like the "Series VII" horns.
- The "Series VII" and "VIII" horns look too much like each other.

I really have no idea when the production on these models stopped. I'm just assuming that they were produced up until the next Buffet model, which has RH bell keys.

More comments from SAKTEK:
"[These models have] four octave key vents -- two on the sides of the neck, if you look carefully [and two on the body]. I fixed a tenor like this once for a penniless guitar playing friend. It had 60 year old pads, and he had no money so I kind of got it back together like a student model horn -- and it played! That's the sign that the dimensions of the design are good, because there were still a lot of leaks."

This mechanism looks so much like the new Selmer Harmonic models, one wonders if Selmer copied the design from Buffet.

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Techie Notes:
- An example of the engraving.
- Keyed range from low Bb to high F.
- Silver keytouches, reminiscient of the Conn Connqueror models.
- LH bell keys, also reminiscient of the Conns.
- Keywork is hinged only on one side. This may be to increase speed/response.
- Reinforced keywork.
- May have been a couple of models of these horns: the examples I have above have different chromatic F# keys and slightly different keywork.