Are you talking about the stove pipe which is normally on the passenger side? It is about 45mm round and about 6-7 inches long? I got your PM and will send the scans you needed but wont be home to do that until friday. The only one I remember seeing on the drivers side was the insulated one you spoke of that attaches directly to the choke mechanism on the carby as the bi-metal strip/springs heat source.

The stove pipe connects to the underside of the aircleaner snout to draw warmer air only during warm-up to make for a more stable idle/quicker choke release.

Dave.