Webwench,
First of all, I am very impressed that you are doing your own work! I love doing my own stuff... most people think I'm crazy for doing so much of mine on my own!

The wires hanging down there, I don't remember that on my 84 300D but the other items, the VDO part, goes to your Cruise Control. You could disconnect the linkage that goes over to it and disconnect the electrical wires to it and you'd be fine. The black tubing coming off of the injector pump I believe is the vacuum system vent tube that usually goes through the rubber boot of your firewall and vents to the cabin..... it is easy to pull that piece or other vacuum lines loose or out when changing the oil... would seem Mercedes could've designed a better way to get the vacuum lines routed around the Oil Filter housing.....

I have a crude diagram of the 1985 model vacuum routing (A close friend of mine bought a 1985 and since I help him fix it when needed, the vacuum was a mess on his when first purchased.

Let me know if you need more info....... as for those wires, you might check to what branch of the wire harness they come out of and then check your schematic in the Haynes manual in the back schematic section.....

Good luck and I hope this helps!

JMH