Thmyl Lbt Jyms Bwnd Llandrwyd Mn Mydya Fayr Guide
Maybe the cipher is: each letter shifted by -1, but with vowels shifted differently? Unlikely.
thmyl → guzly — no.
But apply ROT13 to all:
t→o, h→c, m→h, y→t, l→g → ocht g — no. Look at fayr → likely fair (y→i, common in archaic spelling). mydya → could be media (d→e? No). But mydya → if y=e, then medea (a name). llandrwyd — Welsh place name: Llandrwyd (real? Llandrwyd doesn’t exist, but Llanrwst, Llandrindod). Possibly llandrwyd → Llandrwyd as a proper noun. thmyl lbt jyms bwnd llandrwyd mn mydya fayr
So maybe not Welsh plaintext. thmyl — could be ‘the mill’? t h m y l → remove h, thmyl → ‘themyl’? No. If th = voiced th (as in ‘the’), m y l = ‘meal’? ‘the meal’? But missing e. Maybe the cipher is: each letter shifted by