you have the record, the inner sleeve, the outer jacket, and the plastic cover for the outer jacket.
the inner sleeve is not sealed on an original pressing. it’s open on one side. if it is sealed then you have a re-issue; and there were dozens, maybe hundreds of separate re-issues of various levels of performance for KOB. most of very limited value and very common.
to be viewed as a sealed original pressing; it would have to have the outer plastic cover be completely sealed and never opened. then you would have to satisfy all the other ’tells’ for an original pressing. which are many.
google is your friend; lots of info out there on 6 eye Columbia Kind of Blue original pressings. and then there are the mono versions too. and the white label promo pressings (most desirable of the early pressings). good luck on your research.
the best sounding KOB is the earliest 4 disc single sided Classic Records 45rpm re-issue. it has the corrected speed and is a fantastic transfer. that one will cost you $500 if you can find it. and it does not matter if it’s sealed.