Unfortunately, the vintage Kramer site (I go there a lot) doesn't have much to say about Focus basses, other than they were made in Japan, and not for very long. You might want to try the Kramer Owners Club here on TB; some very knowledgeable people there. If your pickups are original, they are probably
Spectors; that's what my Forum III has. For active pickups, Kramer liked DiMarzios, or Bartolinis (I think). I like older (before Gibson got hold of them) Kramers myself; usually very well made, and underappreciated. I have 3; the Forum, a Duke, and a 450B. Enjoy yours!