
To answer your questions:
1) I have seen at least one pair of SR100 with HP1000 drivers but no red lettering.
2) I have not seen any other Grado models with red lettering other than SR100.
HP1000 drivers also show up in some early SR325, as well as SR100/200/300. The HP1000 drivers didn't get into SR series because Grado Labs ran out of never drivers. It happend BEFORE John had any other drivers other than the HP1000 ones.
BTW you have the nicest collection of Grados. Did you buy the vintage models back when new, if you don't mind me asking? It would be difficult to amass them now!



























