My problem has made me think, so here's to anyone in the industry that's listening:
Most quality mechanical keyboards use Cherry MX switches as do Cherry themselves of course and with good reason - they are great switches! There can be no shortage of tooling capacity or problems with economies of scale when it comes to manufacturing keycap kits in various layouts for switches that many different manufacturers use. The cost of carrying different boxes of plastic keys is insignificant when compared to the cost of carrying complete keyboards in different layouts.
The major problem appears to stem from the commonly accepted vision of an easy to market US 104 key layout as opposed to a difficult or expensive to market series of language defined 105 key layouts. This need not be the case. As far as I am aware, keyboard layouts that are: Austrian, British, Bosnian, Canadian, Croatian, Dutch, Faroese, Finnish, Greek, German, Hungarian, Irish, Italian, Korean, Norwegian, Polish, Portuguese (Brazil and Portugal), Romanian, Russian, Slovene, Spanish, Swedish, Swiss...(etc.) all use the SAME physical 105 key layouts. Only the caps need to change. This is a HUGE market. The same boards could be sold cap-less to everyone, with the cap kit left to final customer choice. You could even have deluxe double shot cap kits, coloured cap kits, etc., etc.
The vision of a keyboard as something defined, packaged, distributed and sold according to the language-defined layout appears to be an illusion that is transforming a business and a customer service opportunity into a problem! Merely two boards appear to cover nearly all the world's needs, 104 and 105 key. The rest is "keycaps"!
Acquiring a different layout on a 105 or 104 touch keyboard should not involve a costly and expensive production run, just a change of readily available caps!
Of course it may also be that there are just too few enthusiasts and quality seekers to make any effort wothwhile for a keyboard manfacturer... but I would find this hard to believe.
