I have a v6 Direct Universal for 1.75mm filament. I had some issues with a jam and broke the black plastic retaining clip that holds the PTFE liner in the top of the cooling assembly. Is this an off the shelf part for standard tubing that can be purchased elsewhere? If so, what is it called and where should i look for it? If not, are their any distributers for E3D in the US that carry this piece? I am making do without it, but it would help to keep the liner centered for better feeding in the extruder. Type A Machines Series 1 2014 with G1 extruder Thanks Russ