The rust is occurring where the superficial chrome plating has broken down and flaked off. There is no treatment
for this. Phosphating the exposed iron will inhibit further rusting where it has occured but not affect the flaking
off of the plating. Naval jelly is one phosphating treatment. Iron phosphate is dark grey to black in color.
Waxing will slow the process but not last long. What you do depends on how you value your time. Best bet is
to keep looking for an aluminum replacement, over which you can agonize about the degree of polish present.