Just my $.02 worth, but the Confederate 1851 Navy brass framed copies were all in .36 caliber, and were made by Griswold & Gunnison (3600+ pistols) and Schneider & Glassick (3 pistols extant). The G&G had a half octagon/half round barrel 7.5" and the S & G had a full octagonal barrel 7.5". No brass framed pistols were made in .44 caliber, and none were made with a 5" "Sheriff" barrel.
So, the .44 Sheriff gun is no where near a clone.
I don't know how historical you wish to present your display. The pistols that I am referring to are made by Pietta (Italy) and therefore have the Pietta "billboards" on the right side of the barrel, "Black Powder Only" on the left side of the barrel, a date stamp and Italian proof marks on the right side of the frame, proof marks on the right side of the barrel, and proof marks on the cylinder.
This is an example of a Pietta S&G, .36 brasser with octagonal barrel. The picture shows a .44 caliber version with a rebated cylinder and cut water table, so check with them to insure it is a .36 before you possibly order.
https://www.emf-company.com/store/pc/1851-Hartford-Navy-Brass-36-7-1-2-110p1164.htm
My Pietta S & G:
View attachment 252854
My Pietta G & G:
View attachment 252856
Both the S & G and the G & G require a smooth, non-engraved cylinder.
Good luck on your office display!
Regards,
Jim