Remove the locks and take them to a locksmith….
RV locks and more
http://www.rvlocksandmore.com/
Atwood furnace manuals…
http://bryantrv.com/docs2/docs/hflamefurn04.pdf
Coleman t-stat manuals…
http://www.rvcomfort.com/pdf_documents/1976376.pdf
it will work fine with the battery removed, make sure to tape the wires to prevent shorting out, and mark the post they come off of…
congratulations on your scoring your new trailer…
Love my mass produced, entry level, built by Lazy American Workers, Hornet