Paint over porcelainized steel

[buckeyedesigns]

Hello all! We are refurbing a 12' x 3' sign cabinet that is 12' in the air. Removing the cabinet is not an option. It was originally an orange porcelain finish but was painted over with blue. The blue is flaking terribly. Any recommendations on what to paint this with? We used our multitool to remove the flaking paint and scuff up the finish. We just need a recomm on primer and paint.

Thanks in advance.