You can try selling them whole, but the most money will be obtained by breaking them down and selling the hubs and rims separate. Some are looking for tubular rims, some are looking for those hubs, but might not want the other piece. Definitely do not bother lacing them up to different rims. You'll probably need to buy new spokes and there will be no more money to be made that way. Also, once you lace up an NOS rim it loses some value as it's no longer "new."

Make sure you pull the freewheel before breaking down the wheels! Or you'll never get it off after.