I just boogered up some of my right side ribs on Wednesday, nothing broken, but I landed hard when the rear wheel on my Harley decided to go horizontal in loose chip gravel. I experimented with some warm up sets this morning, and ribs said "Nuh-uh!"
I'd recommend you don't set an artificial re-start weight. Start with an empty bar and load as for warming up. Or less, if you are feeling it too much. When you get to a threshold in this process where it gets too uncomfortable, make that your re-start weight. Or maybe a little less as you heal.