I stumbled on this by chance:
It looks like it’s been put together by people interested in both Wales/Welsh and Catalonia/Catalan.
It has a rather old=fashioned look, and probably hasn’t been updated for ages, and there are broken links within it, but still there is some interesting stuff, including a quite useful dictionary, and some old Welsh public domain texts, some with translations, including a William Morgan bible, with semi-interlinear English translation.
I didn’t investigate the Catalonian part of it.
Anyway, I hope it’s of interest to some people.
(Oh you might get an annoying pop-up advert, but once you get rid of it, it doesn’t seem to come back)