As far as I can remember, the Roland C.II kit is very nice externally, absolutely barren internally. As can be expected with older kits, a studious modeler would probably want to replace the engine and guns.
Same goes for the Hannover, but again, if memory serves it has exaggerated rib detail on the wings.
That's about the only negative thing I remember about it. It has a reasonable Argus engine, as long as you accept reasonable as being represented by the top quarter only.
I 'd like to get one of those again, the old bubble on card packaging had some outstanding artwork...
You would probably have to go to E-bay for the Hannover, but
Krieger's/Rosemont Hobbies lists the Heller casting of the Walfisch at $4.99; quite inexpensive.