Regarding potential problems, well used A-series cameras sometimes suffer from 'Canon Cough', AKA mirror bearing failure. The A-1 seem especially prone, perhaps because they were used more intensively, but all A models can get the squeak, which becomes progressively worse until the mirror slows and finally fails.
Repair is possible but probably not cost effective compared to hooking another body. There's a kit available on ebay, a hypo with oil, but it treats the symptoms not the cause. That said the AV-1 is a neat camera, aperture priority automated but with exposure compensation and it takes the FD lens range which are still a bargain.