Now that there are some knowledgeable Welsh speakers here,
let's try again for some translations. A previous request proved
fruitless. Let's try literal first, and if the song looks
interesting, then make a metrical translation (you, not me).
In the broadside ballad index at www.erols.com/olsonw see:
1a: ZN2711, title1 = Britain's Valor. tune = Oh, no, no, no, not
yet. Stationers' Register entry on Jan. 21, 1634. The tune for 1a
is probably "I'll never love thee more" = [Scottish] Chevy
Chase. [One of my favorites. ABC of tune = B228 among the
broadside ballad tunes.]
1b: title2 = The Welsh-Mens Glory. tune2 [None indicated]. Cf.
Cf. (both) above with ZN3080.
2: ZN3235, title = Byd Y bigail. tune = daintie new tune. Author
= Terfyn R. H. No Stationers' Register entry, but printed before
the end of 1632:
Cf. ZN1373, ZN3531, and search whole flie for 'Welsh'.