Like you Ivan I have similar reasons for wanting the violets to be called Devon or Parma violets. But a little research has sunk our boat.
Parma violets came from Italy originally and are noted for their sweet scent. Our 'Devon violets' are scentless.
Parma violets are also a well known form of confection with a violet taste that was produced in our home-town.
I can't find any reference to Devon violets except as varieties in flower nursery catalogues. Wild varieties don't seem to exist - double
!
Of the scentless violets I think your example is either Common Dog violet or Hairy violet, I can't tell which from the picture.
Sorry to burst your (our) bubble.
I hope somebody tells me I'm wrong.