Fuel gauge sender Options

[HalfMoon]

My fuel sender is not registering anything below 1/4 tank.
As you might expect, in an ohm test I'm not getting w=0, G=70-100 (empty) or w=infinite, G=1-10 (full).
The thing that's odd....the wire is intact it's entire length, all contacts and the wire (and ground wire) were cleaned until cotton swabs were no longer returning dirt, points of contact the floater to the wires is good yet a continuity test towards the bottom of the sender wire/s shows fading continuity until none.
Is it possible for the copper wire to simply lose it's capacity to conduct over 44 years (as I believe the sender to be the original)?
Is it possible the internals of the flaoter are corrupt (hmmm...must do a continuity test those contact point tomorrow).
Yes, I'm aware I can go out a buy a new one. I'd rather learn how to fix a broken one. Why? Because I want to.
Soooo, anyone wanna chime in their experience?
Thanx