Poste Gambetta entrance to Pere-Lachaise - postcard

Located on the northeastern side of the cemetery Porte Gambetta is the terminus of avenue du Pere-Lachaise and is the other major entrance (after Porte Principale off of boulevard Menilmontant). You can just make out the crematorium and columbarium in the background.

Notice the changes in the gate structure? Which is the older of the two? My money is on the bottom one