.69 caliber, 42" round barrel. Lock is marked on the front Butterfields Patent Dec 11, 1855 Philada. Marked in the rear of lockplate Phila 1836. A copper band over the top barrel about .5" from the breech. Walnut stock with three barrel bands and a extra iron strap on the bottom just behind the rear barrel band. What is interesting about this conversion is that it is a one-of-kind; the barrel was made so it would tip up. There is a specimen illustrated in the book by Lewis Winant, Early Percussion Firearms, 1959: page 190.
All metal surfaces have an even brown patina and covered evenly with pitting. The lock markings in front are not readable; markings in the rear are readable. Stock, however, has is very sharp and crisp with nice sharp line and blackened open-grained look with a very crisp cartouche "NWP." Nathan W. Patch was a Ordinance inspector from 1831-1849. This is a very rare conversion of the breechloading system.