Siamese Model 1903 (identical to the Austrian M1888) bayonet.
Known in Siam as a “46th Year Type Bayonet”. Has Roman Numeral type stamp to ricasso which means they were surplused from Rumania. Austrian serial number 5221 to crossguard and Siamese script/numbers to the pommel end. (Reference JN 169/1 and K #546,547)