OK I see what you are saying

I have all the bolts holding the bracket off, besides the interior from-behind bolt

Any suggestions where to start from under to reach this last bolt?

I also did some more searching, and found this post here
http://www.peachparts.com/shopforum/tech-help/267052-help-e420-1994-power-steering-pump-removal.html

which links over to this DIY with pics
Photo DIY- Steering Pump Overhaul - Mercedes-Benz Forum

even tho thats a w140 and not a w124, the engine m104(?) is the same(the v8)