Completing the model #2

I've quickly checked the model against Solina schematics, identified major lacking elements.
(answering also @farvardin on completeness of implementation)

In the original, the 4' and 8' sections are known as violin and viola respectively.

1. missing: brass section (trumpet/horn)
   It's needed to identify what does the formant circuit folllowing the oscillator.
   It has a set of switches which seem to affect a characteristic of a filter.
   

2. missing: bass section
   It's cello and contrabass, and it has a more complex circuitry, of which I'm not fully sure how it fits in the model.
   It's made from various parts: low-tone selection, clipper, trigger suppression, bass sustain, and low-pass filter