ways to fix a bb sized hole in a head?

[kcducttaper]

I bought an engine on ebay and when it arrived, I found a bb sized hole next to the exhaust port. I contacted the seller (who sounds like a 17 year old high-school drop-out) and after claiming it was a port (railed him for BS on that), he suggested to pay to have it welded rather than sending it back.

My major concern with this is if dirt and junk has already gotten into the head while it was running, the valve stems, seals, and cam could all be messed up already and I just don't want to deal with that. What do you guys think?

(Yes, the pictures are massive. Sorry 'bout that.)

[maxwedge]

Where does the other end of that hole go to?

[kcducttaper]

The best I can tell, without taking the cover off, is that it just opens up to the inside of the head.

[maxwedge]

Well that does not answer the question, coolant area, port, but no coolant?