Out of curiousity, when you were testing the board without the ROM SIMMs, you did have the jumper installed next to the SIMM slot, right? If that's not installed, the computer will just sit there, doing nothing. I'm not 100% certain what would happen if the jumper is installed and a ROM SIMM is in the slot. It should ignore the slot, but, if the jumper was present at all times, that might be why the computer did the chimes of death with the various SIMMs.

Re: the corrosion, it might be a good idea to get some deoxit and clean the pins, just to see what happens. Who knows, it may just come back to life, in which case, you just need to get a new battery holder, or run some wires to a triple AA battery holder and use 1.2 volt rechargeables in that.

-J