To follow up on the idea of out with the old & in with the new century (sort of).

How about the oldest & newest light houses in each region (East Coast, West Coast, Gulf, Great Lakes). If people are hot on "pairs" the could be sold as pairs. Then, for those that like "series" (Stamps, Southern Belles, Lady Light Keeper, etc.) we could have a series of pairs.

May need a new Curio just for the new series. ;-)