Ignore whoever the hell Nixon is. If the pump is working fine, leave it there. It looks very much like one from an old K-Jet Audi, possibly an 80 or 90.
These (as I think Danny's said) have a bottom feed tank, so don't need the lift pump, which is the in-tank pump fitted to the Golfs, which have a top-feed tank. The Audi pumps look just like what you have and have a simple metal bracket that bolts under the car, with space for an inline pump (just like yours) on one side and a filter/accumulator on the other. A scrapyard mission, or call to someone like All Audi in Bristol might yield the neat braket that will allow you to secure the pump and accumulator under your van.
I'm confident that you will have a return, as the 2WD T25 tank *as I recall* has feed one side, return the other. The only minor issue you might encounter is fuel starvation on low fuel level and hard cornering - there's no 'swirl pot', so the pick up might take the odd gasp of air, although the 'acculmulator' (big silver cannister) will help to eliminate sensitivity to this in your situation. Someone might correct me on this, but the only filter you should have is also the accumulator. remove any other filters fitted on the set up, as they might screw your fuel pressure under load, causing the motor to run lean and go into detonation.
Bear in mind that the injection pump on T25s was only held on with a single clamp, which regularly rusts out and is replaced with a ziptie by most.
Don't get bent out of shape over this. Make the wiring safe and at most get a fuel system pressure test run by a specialist to ensure you're not running low pressure, which WILL kill the engine.
