Hi there,
I believe you should be able to recover. Shutdown (turn OFF) the crashed PDC that you re-installed NT on. Go back to your BDC and run servermanager to promote it to PDC. When its already a PDC, power of the crashed original PDC and re-install and set up as a BDC. Once everything is sync, you have to option to demote the PDC back to being a BDC orginally and promote the repaired PDC to PDC.