There we a few at various times at Tucson, KTUS, on the west side sandwiched between 3/21 and 11/29. I don’t know the name of the company there, but they refurbish and sell the aircraft off to others or part them out.
On Google Earth, the 2011 coverage shows at least one WN 737 there on the NW corner of the company I mentioned above. coordinates are: Lat: 32-07-41.82 by long: - 110-57-33.0. Appears like it is a 737-3H3.