603 broken timing chain
 

On a 1987 300D, the timing chain broke and the cam towers have broken as a result. If one were to replace the cam towers and the chain, would this engine Fire back to life or is it an interference engine?

The valve heads that made contact will fall off into the engine... You need to pull the head and replace them.

When I broke a Timing Belt (at idle speed) on My Volvo Diesel it bent some valves.

You won't really know till the head is off.

A cursory check would be to remove anything like the Camshaft that would hold any of the valves open and get an adapter so you can put compressed air into the Cylinder.
If there is a problem with the Valves you should hear Air hissing out of the intake or exhaust ports on the Head.