I am looking to buy the cheap AD584LH (LH version is higher stability, inside metal can) voltage reference to be used for checking multimeters in my lab. I plan to build an enclosure and have it calibrated at a cal lab so that I could base future measurements on that. I know the AD584LH is not being manufactured anymore so what they are selling must be new old stock or even salvaged components which doesn't bother me at all considering the increased stability of an aged voltage reference.
However I am noticing two different style of marking in seller pictures, one style has laser etched part number while the other appears to have the part number silk-screened with black ink.
In your experience what should the original one look like? Or did they make them both style originally?