name='Moor Larkin']Flicking through old 1950's copies of the BBC magazine, "Radio Times", it is evident that broadcasts of Welsh programmes in the Welsh language were an everyday event even back then. The BBC is currently making a popular programme (Torchwood) based in and around the city docklands of Cardiff. I've noticed a number of other popular BBC productions recently seem to be labelled as made by BBC Scotland on the credits.
Wales had it's own independent TV company for some years:
The Harlech House of Graphics
Wales seems to have been as frequent a location for British movies over the years as any other region of the UK. It certainly produced some of the greatest British film actors as well. I have to say I'm unaware of the Scottish film production studios you imply existed.