American Industrial Werks was contracted to disassemble and reassemble a clean room in IL. The customer transported the equipment once it was packed and stored it in a location in IL. The warehouse was next door to the location that it would be rebuilt. AIW rebuilt the clean room at the new location but pieces of the room ended up missing. AIW never had control of the inventory. AIW's contract specifically stated that we would not be responsible for any missing pieces which the client signed. During the rebuilding process some of the plexiglass broke (as used plexi- glass can become brittle if not stored properly). AIW gave a credit to replace broken plexi-glass. However the client has been holding back $55K of payment because they do not wish to pay because they are missing $1500 worth of gaskets. We have already credited items that we do not believe we were responsible for (pieces that arrived broken from the warehouse) but wanted to move the payment process along as the client prolonged the job and final inspections to delay payment. I have signed estimates with terms listed clearly on the documents. The payment was to be paid upon completion. This job began in October and experienced multiple delays and the customer's key people being out of town to avoid final inspections to record completion. This multiple phase job was finished on Jan 11, 2019.