Yes, Italian is very useful for learning Welsh!
About transcriptions, there’s two different things I have and used for two different kinds of practice:
a pdf file with the actual lyrics I found on Discogs (just a few) and in a booklet I got from the label, with all the songs from Wyau/Pyst and Libertino - that then you’re going to have to buy too.
my attempts of transcriptions of other songs, that are those I plan to use for the challenge along with more I still haven’t tried to write at all
(BTW after drinking enough gin I read one aloud one to Pat of Datblygu first time I met her. She was really amused and at the same time very impressed, cause most of my italwelshglish was accurate enough to be understood as Welsh words!
p.s. sending the list in pvt