The naval museum outside Lima has a series of nice displays of deck weapons. When I visited in 2000 I vividly remember a 37mm 5-barreled (gatling-type) revolving Hotchkiss gun mounted on a pedestal with a big crank on the right hand side. The receiver was all brass, and beautifully polished.
I'll now see if I can find a picture online, and check the dates of that weapon.
(edit) Dates are good, advertised for sale in 1874 and possibly earlier.
Here's a wonderful animation of the weapon:
http://www.youtube.com/watch?v=GkOP8LwdmggYou can probably still order 28mm miniatures of this gun from whomever is still casting the 'Houston's Guns' range.
Chick