7 1/2 is the most common.... Though field conversions existed.
BB Cody owned a 5 3/4 Conversion.
Guns of the Old West did a feature story on the orginal which sold at auction for: $22,500.00
Kirst Strite made a replica for the same article.
Jay Strite field shortend mine
and here is my stylized version of the Cody holster for it.