What I once read about the subject of watch dials marked Swiss / Swiss Made and even Suisse or Fab (rique) Suisse on dials was to do with tax laws in the UK (and the then British Empire), France, the USA and other countries, was that watches assembled and sold in the said country (from mainly Swiss parts) were devoid of the punitive taxes but had unmarked country of manufacture dials (or marked by the country they were assembled in) but was the same as the Swiss version except it wasn't assembled by 'master craftsmen bent over wooden benches in the candlelight hand making every single part with total dedication to their craft'...
The 1971 date you give is most likely when the EC (Common Market), now the EU, started aligning tax laws and the Swiss had no option but to comply to simplify VAT and import duties to a multitude of european countries under the EC banner.