- reverse engineer the comms protocol to the display
Pretty thorough waste of time.
2) throw the board out and hook to the load cells with a load cell board,
Much better idea.
The ZU05-U6 legend suggests its a SoC under the blob.
The other component is a silicon strain gauge/load cell perhaps?
Would appear to be the strain gauge amplifier/ digitiser, but guessing its interface is likely to be impractical.
that is assuming the load cells are standard and not some strange custom thing, and if that is the case things just got harder
They are very standard, with the three wires - red, black and white - each and all four connected as a self-compensating bridge.
You want a HX711 module to replace your board and interface to an Arduino.