100W light bulbs? I guess you're referring to grainy photographs - I do need to buy a decent camera but then I'd probably not want to use it in one hand whilst I fix the car with the other - I wouldn't want to drop a good camera!
Vacuum vacuum vacuum...
There's loads of information about the vacuum connections and transmission adjustments over on BenzWorld
DIY W123 Transmission Diagnose and Adjustment 722.xx OM 616-7 - Benzworld.org - Mercedes-Benz Discussion Forum
(Lots of the information from Govert too!)
But if you have a "bitsa" car (bits of this bits of that) I think you need to find out what sort of IP you have - there are probably 2 identification plates on it => one for the pump one for the governor. I guess the original pump would have been a MW/RSF pump - have a look through chapter 07-001 on the (NON TURBO now!) FSM
You then might be able to make head or tail of it all.
The 722.118 vacuum only transmission is a bit of a strange one from what I can make out. There is an earlier 722.118 that had the throttle linkage but not vacuum but MB didn't see fit to give the new 722.118 a different number or anything. Does your existing transmission have vacuum as well as a throttle linkage?
Anyway it sounds like you are planning on replacing it with your spare 722.118 - if you do then you can delete the botched throttle linkage to the transmission which should hopefully help. Don't chuck the old 722.1 transmission, however, as you might want to get some spare parts from it. The splined shafts for example tend to die in an abused 722.1 =>
Advice req'd:- shaft spline wear / measurements / possible fix 722.118 transmission