Hi Rob, not sure if it's of use, but I have two Genuine VW NOS metal tubes, the ones which run from just inside the heater channels by the bottom of the A post the the top of the A post where they connect into the warm air vents in the corner of the windscreen. Not a great description, but hopefully it gives an idea of the two metal corrugated tubes I have. There is a small tab spot welded to each of them at one end, I was told this was to attaché them just inside the heater channel, they were for a 52/53 Beetle & match exactly what I had on my 52 split, only they were not required.