Gas Tank questions W126

[MS Fowler]

The '91 300SE I bought as a "parts car" for my '82 300SD is just too nice to part out....maybe
The fuel system is a wreck---pump and filter clogged with reddish black thick goo. I have pulled the tank and cleaned it, but this tube ( see picture) is broke off at the bottom...what is it? Is it broken? Can it be fixed? NOTE--Picture got flipped over.

Is it likely that the same goo has corrupted the entire injection system?
How can go about getting fuel to the engine? I have a new strainer on order, and new pump and filter in hand. The plastic piece inside the tank that the strainer screws into is loose---I can get it back to the hole, but is that sufficient?

Or---should I just transplant my 3.0 turbo diesel and its transmission and springs and exhaust and fuel components into the SE chassis? Biggest problem I see is diesel pump shut off. Could I use a linear actuator to move the shut off lever?