Hi Leon,
Benalder was delivered 10/1972, Benavon 01/1973 and Benarty (City of Edinburgh) 11/1973.
The A-class did not had a Bridge elevation, A.P.Moller is not an A-class but a S/C-class vessel.
It all started in 2011, as you mentioned. I don't have all the dates for all the specific vessels but besides the classes you have mentioned also the Singapore flag A-class (different from the Danish Odense built A-class) i.e Alfirk, Algol, Altair and Antares had Bridge elevation and the Singapore /Hong Kong flag L-class had a bridge elevation. In this class the last eight were delivered with elevated bridge and the first eight (La Paz, Laguna, Lavras, Lebu, Leticia, Lima, Lirquen and Luz) were elevated at a later date (first 5-year drydock).
Also the ex-Dutch flagged S-class, i.e. Stepnica, Salalah, Salinah, Savannah and Stockholm did had a bridge elevation during their first 5-yearly drydock.
The G-class you mentioned exists of the original 6 g-class vessels and 6 m-class vessels which were renamed with g-names when the triple-e's were delivered.
I'm unaware of any website having all the rebuilding/modification dates readily available but they all have been done at a scheduled 5-yearly drydock.
Cheers,
Roy