Markings will differ depending on where the underlying rifle was originally built as well as where it was converted.  For example, Leige-built examples will show Liege proof markings on the barrel and possibly elsewhere but are unlikely to exhibit other builder or armory markings.

 

   For Spanish-built rifles, markings on the forward section of the lock plate may include, for example, Ybarzabal of Eiber, Orbea Hermanos y Cie of Eibar, and Euscalduna of Placencia denoting where manufactured.  For rifles originally manufactured at the Oviedo armory, the lockplate will be marked with a monogram or cypher Crown over styalized  “AR.” over “O.” over a year.  This might indicate either year of manufacture or year of conversion, but the “O” indicates that it was undertaken at the Oviedo Armory. If the breech block is also stamped with AR.O. this would indicates that the rifle returned to the Armory to be converted and that the conversion was accomplished with Spanish-manufactured parts.  Unmarked breech systems are most likely to have been Remington-manufactured under contract to Berdan.

 

  Serial numbers may be found on the tail of the lockplate, left side of the barrel and trigger guard tang. Breech blocks are likely to carry either a serial number or production number on the underside of the block.

 

  Serial numbers also appear on the lower buttstock.  On some versions serial numbers are found on the barrel bands as well.

 

 

A Special Note regarding the Crown over “AR.” over “O.” marking:

  

  It has been asserted, including previously here on this site, that the “AR.” markings on the lockplate (as well as being prominently featured on Oviedo-manufactured M1871 & M1871/89 Spanish Remington and the M1891 Spanish Remington rifles right receiver flats)  initially signified Amadeo Rey, for King Amadeo I who reigned from 1870-1873 and was coincidentally followed by King Alfonso XII, the Spanish king who reigned from 1874-1888 (thus Alfonso Rey), and further coincidentally was followed by his son, King Alfonso XIII who reigned from 1888 until 1902 (still Alfonso Rey).  We say “coincidentally” because all three of these monarchs’ first names began with “A” so a change in monarch would not have necessitated altering the receiver markings throughout the whole of the production run of the Spanish-built rolling blocks.

  

   But Layman asserts that the AR markings indicate “Armeria.” so that “AR. O.” would be Armeria Oviedo (Oviedo Arsenal).   Juan L. Calvó, a noted Spanish collector and researcher whose work is followed by Spanish authors, has indicated that the markings reference Artillería Oviedo, which, while Artillería can translate directly to "Artillery," in Spanish which would not likely make sense, it also translates to "Ordnance" which would also be a legitimate fit. 

 

   And why an Oviedo marking would be stylized so we have no idea but in support of Mr. Calvó, we note that in this period very many manufacturers adopted crowns as a part of their manufacturing “House.”  (examples can be found at:   https://www.nramuseum.org/media/940944/proofmarks.pdf and others.) 

 

   In support of the original thesis, note that the Spanish have not only bought British-produced arms since the late 1700’s but also closely followed British design all the way until adoption of the M1871 Remington.  In that regard, British royal arms have long been produced with the then reigning monarch’s cypher as far back as the Brown Bess, examples of which the Spanish purchased.  The Brown Bess’s cypher, a Crown over “G.R.” (Georgius Rex or King George), was later followed by the nearly as famous British Pattern 1853 (P53) musket with the cypher of Queen Victoria, a Crown over “V.R.”  The Spanish precursors to the M1867 conversions were the Modelos 1854, 1857 & 1858 which were all close copies of the British P53 short rifles  It is in nowise a stretch to consider that the Crown over AR. might be the Spanish following the British pattern.  Any confirmation of what the Crown over AR.O. via pre-contemporary sources would be greatly appreciated.

 

At this point we are simply uncertain and have not been able to independently verify any of these suggestions regarding the “AR” portion of the receiver markings.