9 volt battery?
in the tender?
that is the battery for the sound..
Are the wheels metal? If so, you have an older track-powered "Big Hauler"..
depending on its "generation" it could be worth $10 to $50 or so used..
but dont worry about "ruining" it..its not a valuable collectible!

paint it, modify it, do whatever you want to it..
see here for help in identifying the "generation" you have:
http://www.girr.org/girr/tips/tips1/big_hauler_tips.htmlWhat does "DD" mean?

no idea what you are saying there..
Scot