Here's a thread for the carriers that I have done for Germany, so far I have the Graf Zeppelin and the Weser.
First up us the Graf Zeppelin in her original congifuration, with a projected completion either very late 39 or early 40.
In mid-1940 her bow was rebuilt along similar lines to that of the Admiral Hipper, Scharnhorst and Bismarck classes to improve her seakpeeking in Atlantic swells.
By 1942 work resumed and some features were redesigned/added to improve on the carrier, all single 20mm mounts were replaced with quad mounts (and one extra added on the stern), an extra 105mm mount was added. The deck and plane handling equimpent was strengthened to hande conversions of land-based airplanes, the masts were redesigned to mount radars, and an armored fighter-director cab, bulges were added to improve stability and the funnel cap was enlarged.
The Weser was a convertion of the heavy cruiser Seydlitz, which was 95 percent complete when work on her as a cruiser stopped. The entire superstructure apart from her funnel was razed, and an enirely new structure was built. She would have carried 20 aircraft; 10 BF-109s and 10 JU-87s.