Mercedes 230E owners please help!

Please can someone tell me where the vacuum hose on the distributor (for the ignition advance/retard) plugs into?
It's a white plastic hose coming from the vacuum capsule which is
attached to the distributor. It is plugged in at the distributor end, however I can't figure out where the other end goes. It looks as if it'll stretch to underneath the inlet manifold or to the left hand edge (battery side) of the car where there is some other wiring.
I gather from this newsgroup that it should attach to somewhere on the inlet manifold or a vacuum connection unit somewhere. I have searched and still can't see anywhere logical it could go.
I have a Merc 230E 1984 W123, 102 engine
Please can someone have a look at theirs and describe exactly where this hose goes?
Many thanks,

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