Welsh tartan is still going strong. There are many shops that sell it. And Welsh kilts. I don't know much about it, because actually, my family is of Scottish decent and I am part of the Gunn clan. My surname is Wilson see and my family originally come from Nairn and were Gaelic speakers. At some point we switched to Welsh.
I should do more research on Welsh tartan and will keep you updated.
Gwlad, gwlad, pleidiol wyf i´m gwlad
Tra môr yn fur
I'r bur hoff bau
O bydded i´r heniaith barhau