I would not be surprised if they created a new brand for those two and other heavy machinery we might get in the future. Would make sense imo, since Cat and Hitachi or Komatsu are basically just that.
My wild guess is FPU. This acronym formes from the polish words "Fabryka Pojazdów Użytkowych" which roughly translates to "Utilitarian Vehicles Factory". It would also kind of makes sense since Eastern Europe is a home to irl large haulers brand: Belaz.
Most trailer manufactures, including Randolph Ohio's Eastern Manufacturing, stick to trailers/similar upfits. The one I can think of that is worth mentioning is Brandt as they do manufacture trailers and modify/distribute heavy equipment, including mining equipment. The closest they have to this stuff is modified John Deere loaders and articulated dump trucks.