I would expect any well designed multiple lockup system, using modern strong alloy steels and oversize locking surfaces to hold up well. Oversize hinge pin, cross bolt, and underlug would seem plenty. Modern Merkels would seem to be good choice. Only "problems" I see with my 100 or so year old hammer doubles is the "soft", low-C steels they are made of, as well as, sometimes smaller locking surfaces than might be desirable.

Niklas