Yep, as everyone has pointed out, it's a kickstart ROM switcher. Looks like the one I have in my A500. Made by ICD (I think) and it's an Auto changer, you just hold down Ctrl-Amiga-Amiga for 5 seconds, you will hear a beep, let go and the Amiga boots to the other ROM. There is a Jumper on board which allows you to define the default ROM you would like to boot from. There is also a flylead with IC pin clip attached, which has to go to a Gary pin for some required signal (Reset I think).
If you have removed that device, have you been testing the machine with it plugged in correctly? You do have something in the ROM socket, right? I can probably find the settings for you if you'd like. :-)
BTW, if it was mine, I'd keep it and remove the 2.05 ROM and replace it with a 3.1. That way you can still have 1.3 easily if you need it to play that old classic game you liked :-D :lol:
EDIT::: YAY, just got promoted to technoid :-D