Closing the gap between manufacturing financials and the on-the-floor reality?

Looking to connect with anyone who has been sourcing deals with discrete manufacturers. In smaller family run shops, I have found that what the financials look like don't tell the story of what is actually happening in operations. How have you handled that portion of your due diligence in the past? I am looking to connect with ETA Operators who have dealt with this pre and post close in the past and how we can prevent issues for others in the future.