Is overspray on cylinder head ok?

I think it'll be alright to be honest.

It's probably a razor blade rebuild, judging on the quality of the visible gasket surfaces.

If it was me:

1. I'd pull the pan and look at the main and rod bearings. All of them. Minimum spot check a couple clearances with platigage.

2. I'd inspect the oil pump internals.

3. I'd pull the cam and make sure the bearings are installed correctly, the cam turns freely, the cam oil holes are lined up reasonably well.

4. Id pull those rocker assemblies out and use some paint stripper to remove the paint.

5. I'd loosen and retorque the heads in proper sequence.

6. I'd break it in on my run stand.

Basically a laundry list of stuff to make sure that last bit of laziness represented by the over spray is limited to that and not everywhere else.