There is one speaker manufacturer, PMC, that makes transmission line speakers, in the UK. They've been around since the early 1990s.
However, I can find no PMC, or any other speaker, exactly like the speakers you have. None have an Eton woofer, but some older 2-way models do have tweeters that resemble tweeters made by Seas or Vifa.
Also note that your speakers have what could be magnets buried under the veneer that keep grills in place while exposing no attachment hardware. See the black stains in the veneer on either side of the tweeter. Before recent years, very few commercial speaker makers did that.
Like @TLS Guy
mentioned, these could easily be DIY speakers, with nicely done cabinets.
The older PMC twenty.21 speakers have a sloped cabinet front (see below). The tweeter sits further away from the listener than the woofer – an effort to achieve time alignment between the two drivers – something rarely seen today. But those drivers are clearly not the same as yours.
PMC still sells something similar, the present-day PMC twenty5 speakers