Your approach sounds pretty cool with the Zep profiles and then the Princeton. All the old gear sounds cool but I hope you get to us whatever equipment makes the best profiles. I would be interested in purchasing these prolfiles if they get that Zep sound and are just flat out good profiles.
He's used this gear on major label albums with a wide variety of artists - I don't think it's going to be an issue regarding the profile quality. As always I'll have recorded samples of the profiles in action for folks to hear.