You could probably rig something out of a PVC pipe. and super glue that to the orange tip to make it removable. But damn that's a nice pistol. The only thing that killed it for me was the trigger, but I love the gun.
Isaac, I use spray foam for the "internals", but it can be a picky SOB sometimes. Is it possible to take out the outer barrel and weld an extension on? If you did that then you could JB weld the PVC on to that.
I was thinking about doing something like this but I'm not sure if it'll work, I think I'l try to weld the pipe to the homemade silencer then I'l try to grind ridges around the little pipe and rap rubber bands around it to make it fit snug into the tip of the gun.