Mike - no I didn't restore the Mass. state police car. I found it in a display cabinet at a great old-fashioned, brick 'n mortar, train and model kit store in Peabody, Mass called Northeast Trains. They have a strong web presence as well and their track-cleaning car is one of the best around.
Also, for those interested, DD just got in some new stock, including an array of 1/43 New Ray classic 50's-60's era cars (Buick, Caddy, Olds, GTO, 'Vette, etc.) for only $7 each. I picked up all six and will post pics when they arrive.