Opinions - scrap cylinder head?

[Enoch]

What can often happen with these engines is that there are a couple of bolts in the timing chain area that can work loose and get themselves between the chain and lower sprocket. The damage done is the same as when a cam belt breaks. I wouldn't mind betting that's what happened to your engine. Those guides look like bent valves have crashed in to them. I would be very wary about the entire engine and would strip it right down for a really good look, all those bits of metal went somewhere.