Ronald Raygun :
I am making assumptions which I'm not sure are warranted, namely that
it's an easier job to turn the thing around[*], re-plumb the hose or
pipe connections[*], and shift the knobs, than it is to take the valves
themselves apart and reconfigure their innards.

That wasn't the case here. I swapped the innards round without breaking
into a sweat and without my knees touching the floor. I've also replaced
a worn-out quarter-turn valve in the kitchen tap in about two minutes
using nothing more difficult than a pair of pliers. The construction of
the taps is really pretty simple.

--
Mike Barnes