In case anyone's interested in taking any of these flights for nostalgic purposes.. as of this moment:
10/28, UA flight 737 first/award/upgrade inventory available:
IAD-ORD 6:04am-7:21am, F5, XF0, NF0, XY0, NY4
ORD-DEN 10:37am-12:24pm, F8, XF3, NF2, XY4, NY4
DEN-LAX 1:37pm-3:09pm, F7, XF4, NF3, XY4, NY4
LAX-SFO 4:37pm-5:59pm, F5, XF5, NF3, XY4, NY4