I'd say the safest way to determine the identity of a record is the record itself - the matrix numbers on the vinyl - it's so easy to change the sticker on the vinyl or to simply trade the packaging...sometimes the price is also a guide - first editions are id'ed by sellers so as to fetch more
that being said, show me a collector that hasn't been screwed over at least once...
as for ANATO, yes, you're right, sometimes the only visible change in a edition is only the colour of the obi - but always insist on checking the record itself
there are sites where you can find matrix info and if in doubt check in here - sure you'll get at least 2-3 a$$holes and their "witty" comments but sb will prob. answer your question