You can see the link I have pasted in my earlier post in this thread. The link points to the annual Indian Railways report from 1987. Chambal was introduced as a superfast between Gwalior and Howrah in 1987.
Mr. Madhavrao Scindia, the railway minister who introduced the train, hailed from Gwalior and introduced quite a few originating trains from Gwalior to places like Bombay (Lashkar), Calcutta (Chambal) and Delhi (Shatabdi was intended to originate from Gwalior, but was started from Jhansi due to operational constraints).
Initially the Chambal from Gwalior was number...
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959/960 and was a superfast. I have attached a parliamentary debate which lists all the superfast trains in the country in August, 1988. You can see the Chambal express in the list.
Later, the frequency of the train was increased and it was extended to Agra for one run (Extension sometime between 1988-1990). At the time, the Gwalior train ran with the numbers 2159/60 and the Agra one ran with the numbers 2181/82.
In the 2009-10 interim budget, the Agra train was extended to Mathura.