Léon Piradet was most likely a “private label” — a brand name bought by an offshore firm (likely in the Virgin Islands or Guam) to produce Soviet-powered watches for sale in the USA. Sometimes, the dials and cases were also made in the USSR, while other times, these parts were manufactured elsewhere (e.g. China, France). This was a successful enterprise, judging by the wide range of men's and women's wristwatches produced under this marque.