It just AIN'T the same Alan. The Hasselblad SWC is rectilinearly correct and that is something that cannot be found in a 75mm or 90mm wide angle lenses. In the words of a 1960's rock song "fakin' it ain't makin' it".
OK, but the OP was also considering the 40mm which isn't rectilinearly correct. I was just throwing out another option to think about.