Thank you Alexander. I hope the following is helpful.
https://www.deutsche-digitale-biblio...VO73CRWL5M3GJH
https://lwag.org/forums/showthread_t_2576/
From another site:
"The Industriewerke Heiligenbeil GmbH were a subsidiary of the Schichau-Werke Elbing (mainly known for their shipyrads, but also busy in the field of locomotives, and other "heavy metal"), and worked as a repair shop for aircraft and aviation engines."