In spite of what the seller calls it, I think the model name is actually "Parkwood," one word. Like "Lakewood" and "Brookwood," other Chevy wagon names from that era. From the '61 Chevrolet Wagons Foldout.
Wagon names for the full-sized '61 Chevy: Brookwood = Biscayne trim Parkwood = Bel Air trim Nomad = Impala trim.