However once my latex surgical tubing arrived and I fitted it onto the barbed end of the sensor, I immediately realized it would not work, as it simply did not look right. See top of photo below.
I briefly considered aging the latex—darkening it and giving it cracks—but still I felt this would fall short of the look I was after. After much research I came upon a braided sleeve (at the bottom of the photo) which seems appropriate. Not only does it look Victorian to me, but the black color blends in with the other dark colors of the leather and the sensors.
Now I am looking for a metal finding (or other piece of hardware) to finish off the braid and prevent it from fraying.