Remove the locks and take them to a locksmithโฆ.
RV locks and more
http://www.rvlocksandmore.com/
Atwood furnace manualsโฆ
http://bryantrv.com/docs2/docs/hflamefurn04.pdf
Coleman t-stat manualsโฆ
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 ofโฆ
congratulations on your scoring your new trailerโฆ
Love my mass produced, entry level, built by Lazy American Workers, Hornet