A photocopy is fine. Please note it is of no consequence whether you retained the "original" as long as it was recorded at the County Clerk's office.
Owner's Policy of Title Insurance.
It is useful to know whether you purchased the property subject to anything out of the ordinary so that we can properly draft the contract to include those facts. Note that if there are variations, encroachments, easements, etc., a properly drafted contract that includes these items will be harder for the buyer to walk away from. Also, it is occasionally necessary to contact the company that insured your purchase. Knowing the name of the company and your policy number can be crucial.
Certificate of Occupancy.
It's good to know the "legal use" of the premises, which is not always necessarily the same way in which you used the premises. Also, please provide copies of any permits or amendments to the C/O you may have obtained for work you have had done to the premises.
Also useful for identifying variations, encroachments, etc., and if it was done relatively recently, surrendering a copy may save your buyer a few hundred dollars.
Mortgage Payment Coupons or Statements.
Copies of the most recent coupon or statement for each of your mortgages, which contains the information necessary to provide you with a good estimate of your closing costs. Also, it provides us with the information we will need to order final payoff letters prior to the closing. Please remember that "home equity lines of credit" (HELOCs) are mortgages, and will need to be paid at closing.
Copy of your valid (non-expired) government issued identification (driver license, passport), including any documentation explaining or authorizing other names or variations you have used in the past ten years (maiden name, legally changed name, etc.).