http://www.sparkyswidgets.com/product/leophi/is the microcontrollers the same?
It's a pity the back is covered with glue.
Samba, if you still have your LCD, could you test it for this project ?
By the way, one thing that came to mind after seeing the meter without chip is that you may... still be able to read the meter. The PH-sensor itself gives a very small voltage, the opamp translates it to a higher voltage after which it is read by an ADC in the microcontroller and printed on lcd. What we've tried so far is looking at the output of a microcontroller, but you can try to read its input as well. Arduino has an adc as well. If you can find the right pin, it may be possible to analogread it with your arduino.