do check the crossover as well. the work done on midwoofer indicates a replacement for a burnt voice coil. that means that
1. there is a possibility of some caps get getting fried as well.
2. a burnt VC means the speaker was overdriven, possibly to clipping (unless it was a mega amp driving the bookshelves), clipped signals can damage the tweeters in an instant.
3. (does the undamaged side sound wonderful?) an overdrive on one side means means the other side was probably overdriven too, maybe not to the point of being burnt out.
overall the prognosis is not good. unless you get everything checked you may be throwing good money after bad. you have already spent 1.5 lakhs. whatever you spend on replacement of midwoofer unless you have verified everything else is fine, Chances are that you wills till be disappointed.
I would focus, if possible on recovery of the money. And while you may not want others cheated, your first thing should be to get your own interest protected, its not as if he will not con someone else with another defective speaker even if yours is not on the market