His career until he went blind in his early 70s was as a commercial illustrator specializing in automotive subjects. Some of this was for advertising, other works were commissioned as editorial material for magazines. The latter were usually racing scenes created with pen, watercolor and gouache (as best I can tell), often done in an impressionistic, almost slapdash manner.
Below are some examples that appeared in Automobile Quarterly, a horizontal format hardbound publication (Volume 15, No. 4, 1977). Gotschke's work was in conjunction with an article about the Adler, an automobile company based in Frankfurt-am-Main, Germany.
Due to AQ'a horizontal format (chosen because cars are wider than they are tall, so are best presented that way) combined with my scanner's capabilities, most of the images below are either partial or fragmented. Much of this was because Gotschke's illustrations were splashed across the "gutter" over two facing pages.
Mme Anne-Cécile Rose-Itier who co-drove an Adler Trumpf with Huschke von Hanstein, later Porsche's racing director.