How about some new pictures and an update. I've made some headway one the Turbo, it also looks like I may have created a centrifugal supercharger as well in 1/12th scale, the compressor housing could be used as just that with some slight modification. There will be 3 primary parts, the compressor housing, the turbine housing, and the center section. The center section will have the oil feed and return connections, as well as have the turbine wheel on both ends so that they are visible.
Current assembly from the side
Current assembly from the front
Close up of the rear of the compressor housing
Current state of the 3 pieces