It was held up for a while because I have been using parts from previous constructions and the result was a mess with some parts catching on others and locking the whole structure. But not only do I now have a new back plate but I bit the bullet and bought new material for the various parts.
The mechanism looks simpler now without the fabricted joins, bent and restraightened levers and the numerous drilled holes from previous incarnations of Bessler's wheel, and I aim to finish it as soon as possible.
In my opinion, knowing why it works, I think that Karl might not have fully understood the concept behind it and his comment about it being simple was the result of not having had it fully explained to him. I can imagine Bessler keeping his explanation brief in order to allow the misapprehension of the concept thus avoiding an explanation of the finer points of the device. The design is more sophisticated than might be apparent to an observer and an assumption made about its method of converting the force of gravity to rotary motion, innaccurate. Having said that, it is not a complicated idea and once explained, easily understood.