Puccini opera the French presented proportionately (2,5)
I believe the answer is:
to scale
'proportionately' is the definition.
(I've seen this in another clue)
'puccini opera the french presented' is the wordplay.
'puccini opera' becomes 'tosca' (I've seen this in another clue).
'the french' becomes 'le' ('the' in French).
'presented' says to put letters next to each other.
'tosca'+'le'='TO SCALE'
(Other definitions for to scale that I've seen before include "how a model may be made" , "In the same pro-portions as the original" , "relatively accurate" , "In proportion" , "properly modelled" .)