Old version of my commercial — as before (4)
I believe the answer is:
egad
'old version of my' is the definition.
I can't tell whether this definition defines the answer.
'commercial as before' is the wordplay.
'commercial' becomes 'ad' (abbreviation for advertisement).
'as' becomes 'eg' (I've seen this in other clues).
'before' is a charade indicator (letters next to each other).
'ad' after 'eg' is 'EGAD'.
Can you help me to learn more?
(Other definitions for egad that I've seen before include "traditional oath" , "Forgotten curse" , "Mild oath (archaic)" , "Mild oath - aged (anag)" , "Old exclamation; aged (anagram)" .)