FWIW, the actually useful historical-resurrection 'proofs' generally centre around 'there are non-Christian historians that mention that there was this troublesome cult leader that fits Jesus' profile and that he was crucified' and 'Christianity grew out of the resurrection story and if the authorities could have produced the body they would have done so; whilst the followers could have nicked the body and hidden it, most of them met unpleasant ends which they could have avoided if they'd been willing to say they'd made it all up and here is where the body is, which seems unlikely if they were lying'.

The sources they're using for those facts (there was a preacher, he got crucified, the authorities lost the body, a religion grew relatively quickly out of reports he'd been seen alive again, the people best placed to make it up kept up their story even under torture and penalty of death) seem as solid as any other contempory historical sources - mostly it's the Roman and Jewish historians who were writing around then that they quote.