Yes. 145/146 Navjivan Exp even used to have a "Book library" a cabin in II SL class where you can borrow books such as Twinkle & Amar Chitra Katha. Coaches were numbered as A,B,C,D just as UK style of coach numbering. In 1984, the first AC 2 Tier coach was introduced. 2A Fare was calculated on basis of First Class + 2AC surcharge.
Navjivan Exp & Frontier Mail were also first candidates for cushioned II SL class (from the former wooden II class sleeper bunks).