I have given a deposit on a boat which currently has a leaning post seat. The dealer is to swap out that seat for a reversible pilot seat - this is in the contract. The sale of the boat is subject to sea trial. Since the weather in NY has been too cold to trial the boat, we have not moved forward yet. However, we just recieved a call from the dealer that we MUST close by 2/28/09 or the deal is off. Nowhere on the contract does it give such a closing date. I am reluctant to close without somehow having it in writing that the seat will be swapped out within a reasonable amount of time. Can I make my own addendum to the current contract for the dealer to sign? If so, how do I word this?