The information that Robert West gave in his post of Jan 15, 2005 concerning the two 10" Rodman guns in Santa Monica, CA is correct. I would like to supply some additional data taken from the book "The Big Guns" by Edwin Olmstead, Wayne Stark, Spencer Tucker, published in 1997 by Museum Restoration Service, Alexandria Bay NY. The two guns were orginally cast by the Seyfert, McManus & Co. Foundry at Reading PA in 1864 and 1865 with registry numbers of 102 and 103. The letters MS that may appear on the guns are the initials of the orginal inspector, Morris Schaff. They were altered to a 8" rifle by the West Point Foundry in NY in 1885 and 1886 with the registry numbers 262 and 263. The sleeve to alter them was inserted in through the muzzle and increased the weight of the guns by about 900 pounds from 15,100 pounds to 16,000 pounds. The inspectors for the conversion work were RB (Roger Birnie)for gun #262 in 1885 and DAH (Douglas Alexander Howard)for gun #263 in 1886. The differance of one year is correct. This work was part of an Army plan to modernize and convert obsolete smoothbore guns to rifled artillery. The effort must have been a success in that many of the guns are still here but, of course, no longer used. As they say, the rest is history.
Regards