I went on to Sonorus' home page out of curiosity. There is no pics gallery of older models, but there is a brief history that I will attempt to translate:
Sonorus was founded in 1903 by M. François Panny, after studying with"Selmer Paris". At first they only made wind instruments, but rapidly began making drums & percussion.
In 1936, M. François Panny decided to completely stop the production of wind instruments in order to concentrate on drums & percussion Instruments.
The business was eventually taken over by his son, Gaston Panny.
In 1962, M. Augustijn Biesemans took back Sonorus & bought more machines in view of enlarging production.
En 1994, the firm was taken over by myself, and I brought lots of changes. The look of Sonorus Instruments was changed radically . We are continuing to search for better and more modern production methods in order to guarantee you superior quality.
Felix Conters
and that's it in a nutshell..no model references or colour charts...hope this helps D' Drummer