That is a Watson Stillman crank pin press. Actually that particular one is in our shop in Sheepscot- as that's where that photo was taken (I recognize the grey painted band saw frame behind it).
It's good for 60 tons and, by happy coincidence, is perfectly arranged and sized to mount 20" wheels on two foot gauge axles. That's our intent.
Kind of fun that it's picked up a little following!
See ya
Jason