Look. I would like nothing better than to find a dusty old MCM/70 computer for cheap in some thrift shop and restore it to it's former working glory. Realistically we all know how unlikely this is given that relatively few MCM/70s were ever produced and that it has been close to 50 years since the last one was made. 

So what about recreating the hardware from scratch. Obtain the original schematics and with luck PCB layouts, source the parts, many of which are vintage now and no longer manufactured, and make a replica. While this is might be possible, the endeavor would be very expensive, certainly well beyond the means of the average enthusiast like myself.

Another possibility is to create an emulation of the MCM/70 in software. This is just what the team at the The York University Computer Museum (YUCoM) did. From their web page:

An alternative approach to the direct use of MCM hardware  is to write historically accurate software emulators of this computer destined for modern desktop and laptop computers. Although such emulators do not necessarily reflect the computer's hardware on, say, integrated circuit level, they offer a platform for research of general hardware organization, storage organization, systems and applications software,  etc.

Software emulation is great and is certainly an important part of preserving these wonderful old machines, but I have found that nothing beats the feel of typing on a  physical keyboard and hearing the sounds of the keys clicking. 

So here is where I come in. My plan is to make a full size MCM/70 computer reproduction with a real keyboard and display which I'll integrate into the YUCoM emulator. This physical reproduction will be as accurate as possible but made with modern components and fabrication techniques. For instance, the case will probably be 3D printed. I will add the cassette bays to give an authentic look but at least for my first out they will not be functional, instead using the emulator's virtual cassettes.  Ultimately I will produce an Instructable so that others might make their own MCM/70 should they choose to.