I must correct myself.

Europe/Vaduz in backzone has to be amended with DST 1941/42 .
It cannot be dropped, because it still differs from Europe/Zurich before 1894, as Vaduz did not follow Bern mean time before it switched to Central European time.

   On 2019-07-04 14:11, Alois Treindl sent newspaper excerpts:

In the year 2013 I had contributed information that Swiss neighbor country Liechtenstein, represented by Europe/Vaduz in file backzone, did not have daylight saving time in 1941 and 1942, while Switzerland, represented by Europe/Zurich, did have it.

A colleague sent me a follow-up question today, which cause me to reconsider the question.

I was able to access the online archive of the Vaduz paper Vaterland for free - they offer a special summer deal.

I could confirm frm the paper that Liechtenstein did in fact follow the same DST in 1941 and 1942 as Switzerland did.

The entry Europe/Vaduz in the file backzone can be removed, so that the link Europe/Zurich Europe/Vaduz remains effective even for those who, like me, compile TZ with backzone included.

I attach a few newspaper clippings, not translated.