Of the highest quality (6)
'of the highest quality' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for finest that I've seen before include "Most splendid" , "A1" , "Most delicate or topmost" , "Superior in quality" , "Of the highest quality" .)
(Other definitions for gilt-edged that I've seen before include "Of investments, considered to very safe" , "(Of investments) regarded as extremely reliable" , "Of high quality and reliable" , "Like reliable stocks or securities" .)
'of the highest quality' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for top-notch that I've seen before include "Superb" , "Grade 1" , "Excellent (informal)" , "Wonderful" , "Of the highest quality" .)