Hi Gene,  
AFAIK, the design cast into the backstrap is consistent with the P1845... 
Question though - I see a break in the ribbon bar of the hilt closest to the lens (in the 2nd photo).  Is there a break in the bar, or does the sword have a folding counter guard?  IIRC, the folding guard was dispensed with in the P1845...  
 
Is the portepee original to the sword?