Kyle,
There are 3 (1 gas, 1 LP, 1 Kerosene) in Indiana, 1 LP in Illinois or Missouri, 1 gas was at Massey Days last year, yours and 1 that was for sale on the internet some time back. It went to southern Illinois. In the original post someone said he had found one but they never posted anything else about it.
If I'm remembering right then there are 7 and possibly 8.
Literature shows them built as a 44 Special and a 444 but to my knowledge no one has ever seen one of them.
Tom