Marcel,
I don't know if you read the Railway Preservation (RyPN) Interchange Forum, or the Narrow Gauge Discussion Forum, but folks from one of the museums out west had discussions about their restoration and even had CADD drawings for the Miller Hook couplers (and platforms) they replicated. Randy Hees is now out at Nevada RR Museum, and if it wasn't Nevada, then possibly Western Railway Museum...
I did a quick check on RyPN and found that Mid-Continent restored Milwaukee, Lake Shore & Western Railway #63 and included the Miller Hook couplers on the car.
Dave Crow