Legal response required to avoid litigation in a business

I purchased a business in May 2023. I have attached the SPA. The closing accounts were due 10 days after completion but did not arrived 11th November 2023. My accountant has indicated that there is significant tax owing. Along with the tax that I have already paid, there is significant 'Work in progress' that has been discovered and the potential for more.

The first deferred payment is due which I will seek to pay if the deferred amount is correct. My accountant states that is simply isn't. The sellers lawyer is chasing payment of the deferred amount else court action will follow.

I want to:

1. Challenge the deferred consideration amount and revise the deferred amount

2. Make a claim under my warranties and indemnities (I have to do so within a year) for breech of contract due to late accounts being submitted and 'work in progress' not being declared.