The index page for the 1954 French flap section of this site is here.
Reference number for this case: 30-Oct-54-Mertzen. Thank you for including this reference number in any correspondence with me regarding this case.
[Ref. 1013:] CHRISTIAN VALENTIN:
Journalist Christian Valentin indicates that on October 30, 1954, at 08:00, three young people saw a luminous ball followed by a long tail, passing, between Mertzen and Strueth.
Not looked for yet.
(These keywords are only to help queries and are not implying anything.)
Mertzen, Haut-Rhin, Strueth, boule, luminous, trail
[-] indicates sources which I have not yet checked.