<VV> Is it a Rheostat? - 1960 sending unit

[Secular]

  I'm grateful to Tony U. and Lew R. for assisting me with the
  gas tank sending unit on my 1960 Monza - it's so comforting to 
  know that the gauge isn't lying anymore  :))

  Any hooo, with that malady redressed, I wanna fix the bad unit 
  (bad habit, I know !)
   
  I opened the old unit's rheostat box (it might be called something else, 
  but it sure looks like a variable resistor/rheostat & it's better than 
  saying _thingy_). It appears fairly clean without any obvious 
  disintegration of the contact points or the flat wire which 
  it rides against. 

  A friend told me that the rheostat box from the 61-64 unit will 
  replace the one for the 1960.  

  How do you repair/test this unit? Does it require a mere cleaning 
  with fine sand paper ? Are the rheostat box/covers readily available 
  for 61-64?

  Regards,


  Tony Irani
  Charlotte, NC