Rivarossi was also supposed to do a 4-8-8-4 Big Boy in plastic kit. I do not believe that it went very far as most of these kits came at a time when people stopped building kits. A few modelers have tried to build Big-Boys using two kits of the 0-8-0 and other spare parts.
Rivarossi was very innovative and the Pocher brand (Luxury car kits at 1/8 scale) are also issued from the same Italian factory. They combine plastic and various metal parts and turn into gorgeous museum quality models, with a lot of care.
Yves
