Mani Vijay,
Think it was a GY WDM2 hauling all the way MAS-ADI & back
Yes, travelled first time during March 1979. Used to leave MSB on Tue at 06:00 to arrive ADI next day 17:30. In the early 80's IR shifted dep.point to MAS. Only 2S, 3T-SL, & PC existed. 2AC Sleeper Car introduced later in 1984.
On return left ADI...
more... at 07:00 (Fri) to arrive MAS 20:00 next day on the present day 2163CR/DR-Chennai Express slot from DD.
Rerouted via BZA from 1994-95. It was IR's only few trains which existed with cushioned 3T SL classes as most were of wooden bunks. IR coach numbering designation then was just as present day UK National Rail style like A, B, C, D, etc.
Ah, those wonderful years in dear old Madras/Chennai, way back then!