I was able to find in the family, among other many nice records of Hungarian Folklore Music a Colorvox flexi disc. It seems that Hungarians did way more pressings that the Romanian counterparts (shown in the giga-post Electrecord Fotodisc). A pretty big collection of them can be found on discogs, as Publishing House of the Art Foundation (Képzőművészeti Alap Kiadóvállalat) also released, under the Cityvox label, a series of circular flexi-discs, with a normal cover.
On January 27th, 2025 I managed to record this fotodisc as well, the recording is below.
Madarász Katalin, Gál Gabriella - Sej, Haj Boldizsár ... / Nem Születtem Butyira, Mama ...
ML. 237-102/663
Üdvözlet a Balatonról // Gruss vom Plattensee // Gretings from the Lake Balaton // Привет с Балатона
Photo by: Czeizing