The vacuum diagram In the Bentley is at 24.24 and 24.24a and 24.24b.
There are two sides.  You seem to describe the right. But I'd suggest
consulting the Bentley.

The left is important too since the vacuum advance  and the fuel
pressure get the vacuum source first ON MOST diagrams.

This distributor vacuum Unit has a second nipple which then feeds back
to a tee at the AFM.

Sincerely,

Mark Keller