On another thread I was told that the Cornish and Welsh didn't wear kilts. Can someone confirm the legitimacy of these websites and what is on them?

http://www.welsh-tartan.com/

and here

This company is quoted as saying...
The wearing of a chequered or tartan cloth by our Celtic ancestors is a tradition that can be traced back through the centuries. In the ancient Tumuli (burial grounds) found throughout Cornwall, fragments of tartan cloth have frequently been unearthed. The Romans described the dress of the Western tribes of Britain as being a “loose tunic of chequered material ... drawn in at the waist by a leather belt”. Subsequently, it is from the Roman name given to the Celts that lived in the far South West that our company name of Cornovi is derived.

And these guys......

Or is this all something as simple as saying we all jumped on the kilt train and everybody just made a history to include themselves in the kilt records?

My own investigative understanding was that the kilt was introduced to Celts by the romans.

Cheers lads