Local dignitary of long ago put Into service (8)
I believe the answer is:
mayoress
'local dignitary' is the definition.
(I've seen this before)
'long ago put into service' is the wordplay.
'long ago' becomes 'yore' (I've seen this before).
'put into' indicates putting letters inside.
'service' becomes 'mass' (I've seen this in other clues).
'yore' put into 'mass' is 'MAYORESS'.
'of' is the link.
(Other definitions for mayoress that I've seen before include "Civic dignitary" , "Head of town council" , "Public official" , "Local dignitary" , "Female dignitary" .)