Jotul #4 information

Hello,

The house that we purchased has what we believe to be an older Jotul #4 combifire stove that we have taken out and put into storage. I was wondering if there was any way to tell just how old it is and how good of a condition it is actually in. As far as I can tell, all of the pieces are in tact and functional. We would like to eventually sell it as functional, but only if it is in good working condition. Otherwise, we would probably just list it for parts. Thanks for any information that any of you may be able to provide.