Chinese 1.6 steel roller rockers

I wouldn't suggest using a used shaft with new rockers. and on a side note, if you have the PC shaft, make sure the oil holes are drilled in the right spot, center of rockers. The shafts I got were soft and had most holes drilled under the bearing surface, oiling was poor. I ordered new PRW shafts and fixed the problem.
How big would you drill the holes?

Just weld-up, grind, sand, & polish off the old holes?