This is a Topic thats always been and ALWAYS will be debatable and hard to agree!
Take for example a PRISTINE FLAWLESS model that has been displayed in a dust free environment. Collector kept ALL the original packing/boxes etc. IF that said model were to be placed back into its' original packing and it wasn't mentioned that it was displayed, one would NEVER be able to tell the difference! SO that said some would simply say "Mint in BOX" another seller might list everything I said and say "Was displayed in dust free environment, previously display but shows as NEW and mint" MANY here have a problem with this and there really is no right or wrong answer. To some if it was displayed no matter its current condition then it's NOT mint in box. Others like myself don't care as long as the model IS MINT and nothing is altered, broken or missing and the box is in good shape and all packing present etc.. Still the purist will argue it's only MINT IN BOX ONCE and once opened and or displayed it's no longer Mint In Box. Heck some collectors only want a FACTORY SEALED MODEL that was never opened. GOOD LUCK WITH THAT! Why? Some models suffer from die-cast degradation/zemack cancer. Say you bought a MINT IN BOX never opened FM 1955 Red/black Pontiac, DM 1960 Thunderbird w/sunroof or a CMC Burgandy Horch. Many of these are crumbling away now! Imagine you open it and it's falling apart? Does the seller have any liability in such case if he/she never opened it to inspect it, and you the buyer ONLY want an unopened model? I'd say NO as that buyer only wanted an UNOPENED MODEL so..... it is what it is a crap shot. I won't argue this point or topic as it's beating a dead horse and we will will agree to disagree to agree then disagree some more! LOL Again for ME IF said model arrives pristine, clean, no smells, nothing missing, excellent paint etc. then Im getting a model that IS Mint in box. If it was displayed or gently handled and one couldn't tell then Im fine and accepting of this! Look at that Bellvedere that was buried for about 50 years that was BRAND NEW when vaulted. That was MINT IN VAULT when it was buried, NOT so much when unearthed! LOL