72 Swinger - Some wiring questions.

With the rebuilt 318 its hard to know what cam is in the engine and what distributor they installed. If the distributor still has its tag on the side, then it we can take a look at the books. When they get opened up, and when they get rebuilt by a big operation (eg Cardone) the tag gets tossed. That's not a big loss because they don't neccessarily keep the springs and governer together with the distributor body they came out of.

Why am I going on about this.
Because without knowing the cam and distributor were intended for use with that NOX reduction system, I wouldn't use it.
Even with the original engine and distributor I'd be on the fence. I know the later version (OSAC) made a noticible lag in throttle performance. Enough that it would make you unhappy driving it.

So I say no. If its been OK like that, leave it off. As far as the wires and surviving pieces, I'd probably leave them just to keep the wiring neater and the ends out of the way. For the connector to the missing solonoid I'd use a small zip tie or two. Maybe some electrical tape around the exposed terminals if you think they could contact a ground.