OK we have the trailer and the key Eric gave me for the rear galley hatch lock does not work. Many/Most trailer locks are FIC and there are numbers stamped on the lock and key and they need to match, identification is two letters followed by 300 through 350. The two letters are for who knows what and to order replacement keys you need only the 300 number.
The galley hatch however has an identification number of AE 012 and the FIC key fits (same blank).