I have two of these bikes, and they originally came with spring coiled housing. Aside from finding some of that, your bike shop may have a ferrule that fits the hole correctly, and can hold the housing straight. I haven't found one yet, but I haven't looked really hard either. Luckily, both of my bikes came with the original housing intact. It's the same stuff that Suntour supplied with their bar end friction shifters, and it works perfectly with index shifting, as it does not compress. Also, check that the cable isn't binding in the bottom bracket area, since the cable rides in a groove machined into the BB shell itself. When index cables bind, yhey will shift fine going up. If it doesn't slide easily, it has trouble letting the cable back out. The force of your hand shifting the levers, is stronger than the force of the derailleur spring.,,,,BD

This stuff right here! Sorry for the ebay link, it was the ONLY picture I could find online?

http://cgi.ebay.com/Vintage-Nipon-Me...1e657&x=38&y=7