Has anyone re-surfaced/ re-glazed a bathtub suround?

[Dawn Young]

After moving a nice doublewide manufactured home (1999) from seattle (no hard water) to tri-cities desert (lotsa hard water) after one year of tenants that may not have cleaned the tub surround, the tub went from an almond color to a reddish color.  Scrubbing does nothing for it. It does not appear to be mildew, just hard water?  This is a plastic tub, the surround is much worse than the tub.  We need to find an affordable fix. re-surface kit from homedepot?  Slide in new tub over? Obviously, its not the hilton.  Nor is it a ancient single wide.  My tenants go for "clean" not "fancy"  The other bathtub in the house has only slight discoloration, and is a soaker (bigger) tub.  Please no discouraging comments on it being a mf home, or moving homes.  I know my niche(to an extent!), and am learning stuff all the time.  :-)  Thanks for your help!  It is a rental, but we may sell via payments, or bank loan, which it does qualify for.