Originally Posted by S10 Racer
... It looks like the top plate can be removed.
Sure looks like it to me too S10. It's hard to tell on some of the others (like this one from Speedway) exactly how the unit is attached to the top plate. But with the one you found it seems pretty clear to just be a bolt and then the wiring goes through the plate separately. And if that wiring pass through is easily removable, then all the parts and pieces are right there to cobble together something...just drill two holes in the tank near the filler hole, one to mount the unit and one to pass through the wire.
Thanks for the find.