I don't think there is much Lionel. It is not in my opinion a Lionel converted to 2 rail. Lionel did nothing like that in the Postwar era. Even if a Lionel Berkshire chassis were used, the wheels would have to replaced, or one side insulated for 2 rail.
I think it could be based on a Hines or Pearce kit Mikado. The valve gear looks too simple to me, but I am not a valve gear expert. But the tender looks a lot like the Hines tender I have on a mikado. The water fill hatch casting looks like it is HInes, or All Nation. The boiler could be from a kit as mentioned or scratch built. The detail level looks like 50s-70s era to me.