To tell you honestly I did not prepare even a thing about the Precis/Grammar paper. I only relied on my sense of English usage and some past knowledge about tenses etc apart from giving a brief look at these books I mentioned above. Nor was I ever good at grammatical rules perhaps because I am from the O' Levels stream where English writing is more stressed upon than English grammar. So, I would not be honest in commenting upon the appropriateness of the resource.
Better ask someone good at grammar. I guess Hamza Salick might advice you on it.