Weight was never really a concern - the moving bar (think Mousetrap rather than, say, Arnold Arnold Terminegger) was a mount for air hammers, which are fairly tiny. Like, the one linked in this thread previously weighed ca. 800 grams. The idea is much more clamp than hammer. I agree it's probably overcomplicated, but it's definitely unique - even if it is beyond my engineering skills at the moment.

The previous sentence implies I have any engineering skills; this would be what we in the trade call a "big fat porky pie". =]