Jayson
if you know anyone that can weld ally, you could consider getting them to weld a bead around the end of the pipes.
I believe you can get a tool from B&Q for swaging copper pipes, basically you press dimples into the ends. I have a few ends to get done, for small ally pipes I send them to the workshop for the welder to weld a bead around the end. The main copper pipes down the centre of the car (which I canny remove) I am going to get that swaging tool,.... if I can find it! K