OK it sounds like you installed the 3.1 ROM chips the wrong way, as in backwards. There is a notch on the chip and needs to go on the notch on the socket, if you put them backwards the chips are toast and you need to get new ones. The computer should be ok. Now that scratch is another story. Does it look like it "cut a trace?" You may need to test the trace to see if it is broken.
Note: Also this model computer had incorrect silk screened markings on the board so you might need to put the chips in swapped. You can swap chips back and forth as long as you install the chip with notch. Never put the chip in backwards as this will kill it. (Which I think you already did!)
