That seems an extremely complicated solution. If you are not going to shift and only need a 37x49mm sensor, what about getting a second hand H3D or H4D and the HCD 24mm lens?
What you mean? Change Contax for Hasselblad? No thanks for the following reasons:
1. I'll loose the lens speed of my 45, 80 & 140 lenses...
2. I'll miss the built quality of the C645 lenses
3. The standard zoom (the 50-110) of Hasselblad is a PINA to use in comparison to the Contax 45-90...
4. The 50 to 80mm lens gap of Hasselblad is to much of a gap....
5. I use other equipment if the case requires high sync speed...
6. I'll loose the (perfect) ergonomics of the Contax body....
7. Changing platform is of considerable cost for gaining nothing....
8. My other back next to my Blad CF-39MS is a Sinarback 54H which is my most providing tool (Art repro is what I specialize with among my pro projects) can't be fitted on a Hasselblad H as there is no adapting plate for H cameras available for it.
9. My other system (for use with movements and leaf shutter cases) is Fuji GX-680 which has permanently on it an adapter plate so that one can use C645 backs on it... There is no adapter plate as to use H backs of it.... (there was one, but proved problematic and it was stopped).
10. My Contax line of lenses (all but the 350) I also use on my Nikons with full dedication (of AF too) as I have the JAS adapter... I can't share Blad H lenses on my Nikons...