[CentOS] downgrading packages

After the large update from 7.2 -> 7.3 there is one major problem, the amanda backup packages.

Strange situation, the host is the amanda server is working fine at backing up all my remote clients. But it has an error backing up itself.

The amanda packages did not change version (3.3.3) and I've done no configuration change.

I'm not looking for help debugging this at the moment. Instead I'd like to downgrade the amanda packages to see if the original function can be restored. But when I ask yum to downgrade, there are no packages available. Is it still possible to downgrade just these 4 packages? How? What potential problems?

Jon