Well you know enough to spot the gain of the inverting amplifier was wrong.
Am I right? :
Note that Fig 5 is not a full schematic, you will need a split power supply as well as some decoupling and a decent layout. That is don't expect it to work well on solder less bread board.
split power supply:
I think you mean " a good Vref and GND". Can I use a 5v precision voltage reference for this circuit and for Arduino Aref?