A 19th century Polyphon table top disc musical box, with twelve 20.5cm discs, 26cm wide

Condition Report
Belongs to a deceased estate.
Definitely sounds tuneful!
"I'll take you home again Kathleen", "Private Tommy Atkins" "Good King Wenceslas" "Couplet Anglais" "Sun of my Soul" "Onward Christian Soldiers" "Oh Belle of New York" "The red whtie and blue Brittania" "Oh Come all Ye Faithful" "Hark the Herald" etc
Serial Numbered  146745 
Later screws to the wooden surface which stand proud, but does not impair function. 
Discs are a little rusty and not entirely flat, but contemporary. 
Photo shows no apparent broken teeth to the comb. 
inset piece of celluloid on the top uninscribed. 
Lever on right side unknown purpose?