Although not torn, or ripped, my seat upholstery is worn. I understand that this can be repainted with lacquer. Has anyone tried it? What results? Does it last?

SEM makes some good sprays for dyeing/painting vinyls and leather. Automotive paint supply companies also can custom mix colors for painting seats,, door panels etc. Have used both and had good long lasting results. Good cleaning before spraying is a key in good bonding. The paint shops also sell vinyl prep cleaners to use, highly recommended.

I've done it myself, and had pros do it when I ran body shops.
Vinyl and leather both.
Both methods have held up fine: no wear, peeling, fading, whatever.
Key to adhesion is to get the surfaces clean.