Ohm’s law tells you current = voltage / resistance, so current = 5 / 180 = about 28mA. Normal for an old LED. Changing R111 to be a 470 or even 680 would probably be a good usable value for a modern power LED, the last thing you want is maximum brightness!
You can avoid desoldering anything on the main board by just adding a resistor in series on one leg of the LED. I don’t know how a IIci connects the LED but if by wire that is easiest and you can make it really neat with heat shrink.
(There’s a IIci I want but the seller is asking $399. Looks nice but they won’t say anything about working now, only that it worked when placed in storage “25 years ago”. Certainly looks good but I have my doubts. Still sitting on AU eBay months after it was first listed.)