May I suggest a clarification on “the author … Phra Sirimungla Jarna of Lanna, composed in the year 2063 ‘B.C.’ “ because B.C. commonly stands for ‘Before Christ’[aka Anno Domini - A.D.); where the Buddhist Era is abbreviated ‘B.E’.

As an aside, do you know why this book is written (2063 B.E. or 1520 A.D.) in the old Khmer script instead of the (then ‘newly invented’) Thai script (of the earlier King Ramakamhaeng of Sukhothai; 1835 B.E. or 1292 A.D.)?

We would expect ‘uptake’ of the ‘Sukhothai script’ to a lot better than that - especially in the Monasteries.