http://www.1010tires.com/accessories.asp?pid=VS502
This isn't what was on mine, but maybe the right direction.
Mine was basically two pieces. the valve was threaded on the outside with a small flange at the base. It was inserted through the hole in the rim from the inside (tire side). Then a chrome shaft (threaded on the inside) was threaded onto the valve stem. Of course there were two grommets, one inbetween the valve side and the wheel, and one between the shaft and the wheel. On mine the flange on the valve side cracked and let air leak out. I cannot find a duplicate of it.:dunno: