Type 4 Intake air preheating system parts

[grumble]

hi everyone, 
going nuts trying to find any information about the preheating system on my type 4 motor.
I've scoured the net but can't any pics or reference to it other than an acknowledgement of the system in the Bently manual, section 3 figure 6-3 under aircleaner.
There must have been a bellows type gasket or something that joined the aircleaner inlet to the metal pipe that attaches to the rear tinware but damned if I know what it looks like or where to source a replacement.
Anyone know the part ??

The black part usually has a grommet to seal to the air cleaner, there is a transfer port that bolts the fitting that you have and runs down the front of the red panel to pick up warm air from the cylinder cover to feed the air filter and stop freezing and consequent stalling in cold weather. I should have a couple of them if you don't have it.