My interpretation is the following:
We have here a bust of Francis I (II), Austrian Emperor. Born 1768, Roman emperor Francis II 1792-1806, as Austrian Emperor Francis I 1806 - 1835, died 1835.
See here a portrait:
http://en.wikipedia.org/wiki/File:Francesco_I.jpgThe box honours the late emperor in a classical style, with laurel and item attributed to him. This was fairly common during this period, Biedermeier. Famous examples of such placing a late ruler in a classical panthenon are the reliefs placed around Napoleon I grave in Paris.
The items left and right are things attributed to the emperor. I tend towards symbols of Freemasonry. Francis I was member.
We should also not forget that during this time censorship was rigid. So we no not expect to find any critsism on the Austrian Empire on an offically hallmarked item. All symbols must be politically correct. Symbols from Freemasonry are accepted.
Maybe other members can interpret some items, I have no clue about the Pegasus. But I think the snake represents Napolen (not France, just the person), beaten by the Austrian Empire.
Regards
Jörg