A minor difference is that the horns acquired pearl inlay at some point. The main difference between these two 'models' is the subtraction of the dual-octave key. The award of first is given to the Conn 'Worcester' made in 1888.
Neither is the first model made by FA Buescher. Let's take a look at a chart and see if we can track the major features. There are also a couple of major things to note about each series.
There are unquestionably several 'series' or 'groups' of horns that can be called 'True Tone'.
