In may'78 I have travelled on this great train. It was bearing contemporary Mumbai-Raj Livery and had total 12 coaches including a Pantry car, all second class coaches, with large windows (without safety grills!) with cushioned berths. It was reaching its stops before time (upto 30/40 minutes) through out its route!!
I learnt thru my dad that it was Super Fast and newly introduced at that time.
Most probable date of inauguration should be 1st or 2nd Nov'1977.