[slomotion]

Thank you for the responses!
I'm still on the fence about whether to delete the systems or just clean up and refurbish the whole mess. The van is 100% original and in my indecision am somewhat reluctant to deviate as long as things are working. (The original impulse to delete everything was the result of a couple of vacuum leaks that took a while to find.)
Parrot, you're right, the EGR, air pump, and associated diaphragms had been removed, and I ran up against "what else can go?".
Now the question remains restore or rebuild. If the van had been modified in any way there wouldn't be any question, but although it's not anything really special, it is a 40 year old original.
Decisions, decisions........

Thanks guys!