To my surprise there was another article on the Moswey III, this time in in our local newspaper, the “Zürisee Zeitung”: https://www.zsz.ch/als-in-uznach-segelflugzeuge-gebaut-wurden-879571428937. Unfortunately I cannot reproduce the article here, and it’s hidden by a Paywall, but it’s a nice informative read on the production of the plane in the workshop in Uznach. It also has a nice picture of the restored HB-374.
In the meanwhile the construction of my Moswey III is making progress. The first wing is just about ready to be covered, and I’ve started on wing nr. 2.