Hi guys, I was fortunate enough to get my tag decoded. Here is the info I got.
59=1959, 28=Bonneville, and the 37=Sport coupe (two door hardtop.) Body-PO=Pontiac Michigan Fisher body plant, and the 5092=the sequential body build number. Trim 278=Ivory with Metallic Maroon and Mahogany "Morrokide" Imitation Leather. Paint CC=Cameo Ivory top and bottom. The ACC codes are F=Back-up lamps, B=Heater and defroster, I=E Z Eye glass all windows, KX=Laytex foam cushion front, JX=Instrument panel padded