If you have fuel coming out of everywhere except the injection lines then you may have stuck the plungers when you ran it out of fuel the first time. The diesel is what lubricates the pump.
While the injector lines are off at the injectors and you pump the primer does any fuel come out of them?
You should get something. As for stiff primer you might have already felt it but did not notice the change. Some systems are more noticeably then others. Then to make it worse some primer pumps use a spring to pump the fuel VS when you push on it. But since the line cracked from age then this one is when you push it. You may also here the spring in the return check valve rattling.
But if fuel is coming out of the injectors with the line loose then it should be able to start to build up the pressure when cranking. Just keep in mind that the injection stroke is on a small amount and the hole line needs to fill up. Some systems the primer will push fuel out the injector lines when off some don't. It depends on the system. Feel free to call Margret at Diamond Diesel in West Sacramento to probe her knowledge of 25 years. She may have a trick others don't know about. All they do is injectors, pumps and turbos. She knows your Bosh better then anyone. I think there is a sticky or a link in the diesel section to them. She can also tell you why you don't want China pumps.