It's hard to imagine a broken timing chain on a diesel that does not bend valves at the very least. Charlie is right, if the cam is broken, it's not by coincidence. I also can't imagine someone taking off the head and then putting it back on without completing the job.

I'm suspicious. I would, however, pursue it further. Like Charlie said, as long as pistons are not damaged, and they probably aren't, then you can fix it up by doing the head. You are, however, at that point hoping that the pistons/rings/cylinders are in good shape, you have no way to do a compression check in the current condition.

Best of luck,