I tried creating an original version of the lightly armored Gustav Karl, which only has text descriptions (?).

The Gustav Karl has been made into HG kits in the Type 13 from Gundam UC and the Type 00 from Mobile Suit Gundam Hathaway's Flash, but both are bulky "heavy armored" versions. However, there has also been a long-standing concept for a "lightly armored" Gustav Karl, distinct from these. However, this is only described in text, and there seem to be no design drawings (and there's also the "novel version" of the Gustav Karl, but that's something else entirely).

Therefore, I tried creating an original "lightly armored" version. Reading wikis and such, it seems to be similar to the novel version...

Gustav Karl Light Armor Type | GPO144's Gunpla works