Maybe the way to go is to connect all the wires according to graph identified on the PCB, then manually drag the cips and manually route the wires, just like when making a PCB. So far, "Autoroute" never worked well enough for PCB making.
As for probing the board with by sending 1's with a raspberry, just as a side note, this was the purpose for which JTAG was invented:
https://www.fpga4fun.com/JTAG.html If that damaged board happen to have a JTAG connector on it, you might use the JTAG to flip bits.
As for reversing the schematic, maybe it's no need to do that in order to restore the board. I would try first to rewire the busses by soldering wire-wrapping wires (
https://duckduckgo.com/?q=wrapping+wire&iax=images&ia=images ) directly between the chip's pins, without trying yo rebuild each PCB trace.
Memory chips back then were not so fast, so impedance macing for PCB traces to memory chips was not so critical. It will work with soldered wraping wires.
Of some help while reverse engineer the traces might be to look at the datasheet pinouts first, because memory chip have an address bus and a data bus, plus a few more control lines and the chips (roughly said) connected in parallel to these two busses. In case there are good traces to another memory chip, that might be a hint how to rewire the corroded traces.
No matter the method, it will sink some time, might be easier to buy another defective instrument listed "for parts only", and make sure with the seller that the board of interest may be defective or incomplete, but with an intact PCB.