I tried using Muratic acid to disolve dried paint in an old paint gun cup and after the bubbling, hissing and smoke cleared I had a melted pile of paint gun cup on a piece of wood. Thankfully it was outside.
I would suggest checking the cost of getting them blasted and powdercoated the color that accents the cart.
Stay away from the "chrome" powdercoating unless the coater can show you some samples.