I think there's a slight ambiguity in the word longago in this context.
the longago Deputy Speaker who was killed in the National Assembly when the furniture was flung at him by elected representatives. Source: Salman Rushdie - Shame (1983)
I can't figure out whether it means "the former Deputy speaker" or it means "Deputy speaker who died long time ago"
I found a word long-ago and its explanation in Merriam-Webster, but I'm not sure it's the same word.
Some background on events Salman Rushdie is referring to:
Shahed Ali Patwary was a lawyer and prominent politician. He was elected as member of East Pakistan Provincial Assembly. In 1955 he was elected as Deputy Speaker. On 23 September 1958 he was injured in a fight in the assembly and died two days later.