only Camaro's with deluxe interior will have the arm rests.
Both my 1968 Firebirds had rear arm rests. One was deluxe and the other is base. Both had the ash tray inserted in the arm rest. I don't recall ever seeing one without arm rests.
If you notice I said only Camaros with deluxe interior, I didn't say Firebirds, I know Firebirds have the arm rests, I made that coment because most places try sell Camaro stuff as Firebird stuff