how to verify pup model

[jupzones]

hi all, recently i've been looking to buy some second-hand pups

my question how do i verify that the model im being sold is indeed the one i'm looking for?

i'm looking for the seymour duncan jazz and jb, is there anyway to tell from the pups itself? thanks

 

[trianglebiscuit]

most of em have stickers or engravings stating the model underneath.