What did they do? Is that a Shay boiler? The drive train isn't old Ephiram's design for sure! Actually, the above loco looks like a "Mason Bogie" with another engine under the bunker where a 3 axle truck would "normally" be. Whatever it is called, it looks like a dandy way to use a couple of the Bachmann 2-6-0's, provided smaller drivers could be used.
Just like it has been said-"There's a prototype for everything".
Yes! it is a SHAY boiler, LIMA SN #3185, #'s 3183 & 3184 were converted to 4-6-2s. Built for Estrada de Ferro Osete de Minas in 1922. Osete #302, believed converted in 1930 and
retired in 1930, apparently not a great success!. Only known
The two Pacific's faired a bit better, #339 converted in 1941, destroyed by boiler explosion 1955, #340 converted
1942, retired 1965, on display.