I picked this up today at our monthly coin show. Everything thing at first glance appears good. The weight is right on. The edge looks good. The problem is the assayer's mark. For 1804 Krause only lists TH (Tomás Butrón Miranda & Henrique Buenaventura Azorín) as an assayer's mark. This coin has FM (Francesco Arance y Cobos & Mariano Rodriguez). They show 1803 as the last year for the FM mark. So what do you think? Are there records of the FM being used in 1804? I've checked all of the normal sources but I know we have some specialists here. Thanks in advance for any help.