I have a set of reissue 75 jazz pickups i'm going to use for a pfoject. well in fact i'm going to use the neck one. are they both identical or do i need to use a specific one? one has a part number 048612 with 33753 in chinagraph pencil alongside written on the bottom, while the other has 048613 with 33741. if it matters which one i use, which is which??