I wonder how old it actually is. The grate bars look too fresh to have seen much use (obviously could have been replaced), but somone has certainly managed to crack the back, and theres the bit of rust inside (but that probably happened when it was not running)
You do need to find out what it is though - it could be worth somthing more than just a stove, but i suspect it isnt that old at all (ie a few decades, rather than ancient)