Headgaskets can be reused, not ideal. But clean it up put smear some wellseal over it and just be gentle. I done an engine for my old man, we had it apart numerous times (3 iirc) reused it everytime, and was only a shitty eBay job on a k series rover engine (the ones that eat head gaskets) and its still going to this day never shown any sign of going either. Some one off here brought a used Athena 1.2 from me to reuse.