Turns out the chip I thought was bad was actually fine. I read the diagram wrong and instead there was a bad trace to a different chip. So one bodge wire later and I have a working Osborne 1. #retrocomputing
I upgraded cooling and airflow of my PC so now it runs super cools and not overheating any more. Downside is now I can leave it in the floor or it sucks up too much dust. Now it’s blocking a lot of my paints, but it did make me clean up my desk. At least the motherboard is already microatx, so Maybe finding a more space friendly case won’t be too hard.