Leak at Top of Injector

[treiberg]

Just finished up putting in my new Monark nozzles in my 240D, and really like them. However, I have one slight leak, and it is coming from the connection at the top, where the injector lines mates to the injector. So it looks like the mating surfaces must not be perfectly made, and I have already applied some good force, but leak is still there.

So... questions:
-Is there a way to stop it by possibly smoothing out the mating surfaces, maybe with some grit paper?
-If I need a new injector line, where do you get one, and do they come pre-bent, or are they custom-fit?
-I thought about swapping two injectors to see if this might cure it, and to ID whether it is the line that is bad or the top fitting on the injector. Every time I pull the injector do I need a new heat shield? Do they act like a crush washer and cannot be re-used? They are brand new, just got put in, and hate to have to put in a new one each time I unscrew the injector.

Always appreciate the help!