>2003 -> 2012? No way. Heck you can barely upgrade from 2012 -> 2016.
>
>2003 used a completely different metabase setup than later versions so no way that will migrate unless there's some custom tool that does it explicitly using the Admin APIs. Nothing that is built in for sure though.
>
>Frankly - you'd probably want to make sure you do this manually since so much has changed between these versions.

Thanks, this will probably be the outcome.

I do remember, however, having heard of a third party tool like that a few years ago when an upgrade like that was applicable. I'll try to see if I can find some references to that.