Apart from the very obvious stain to the letter sheet it is in remarkable condition, no other faults at all. The stain, as can be seen in the scans, affects the item through to the last page but not to the back outer part, what significance the 'blots' have is any-ones guess.
All other pictures are only for your information of other available versions for this issue! 350 years Synod of Ayutthaya -KB(I)- (MNH)MiNo.1817 KB(I). They were assigned to propagate Christ´s doctrines in Asia and later held the Synod of Ayutthaya (Siam) in 1664.